That first one is good for ultimate contol of the cheek presentation.  Remember, arch form is art form.  This affects the aesthetics.  The major complaints with saggitals are tooth tipping/flaring.  I know the adams clamp at the back is supposed to help with this.  It may be possible to get another on 2 teeth up from that.  I have no financial investment with this lab and to be quite honest are smaller.  There are definitely bigger labs out there, but Rick was very sweet & accommodating.  

Another issue with saggitals are the lack of applied, continuous pressure.  That's why I like other options better.  In contract to turnkey, a continuously applied, lighter pressure allows the body to adapt and respond better.  It can also give a very nice arch form.

An acrylic between the teeth design does impact the bite/jaws.  To lessen tipping, this design may be used.  The poured acrylic between the teeth can be used like a splint for TMJ/TMD of whicb I am less familiar.  When the acrylic is designed to encapsulate around the teeth, it does prevent tipping more.  The issue with that is that it can effect some elements of TMJ/bite.  It is common knowledge of the top orthos in the world that a bonded RPE will be better than a banded to resolve an open bite.  So... for those with a truely divergent growth pattern, I would strongly advise someone knowledgable.  The TMJ/condyle placement must be monitored!  Why I steer away from DIY.  The Vivos clinicians receive education above what your average dentists get.  I don't recommend speaking with it in as it can lengthen philtrum.

I have learned a lot in this confusing space & so wanted to bring this to light.

Here is the front view to the appliance above.  The dentist will adjust the front bar to keep a balance of the front teeth.  There are some crazy powerful strong springs he offers (above the normal hand-crafted springs) that only 3 labs in the U.S. are licensed for.  Obviously, you don't want flare, so that's what that front bar is supposed to offset.  He can put the 6 springs (or 4 or whatever) in those designs.  You will get more forward movement (palatal) with the acrylic that pushes forward, though.  Such as a Y shape or even some other ones.  Obviously, you don't want to be doing this yourself (root absorbtion, teeth pulling from bone - which CBCT shows, other complications that arise).  The bar in the front is controlled by the little wire bubbles near canines.  This way, you don't lose forward growth.  The bubble on the wire can be manipilated many different ways to varying effects.  It is not just for tightening and widening in a flat dimension, if that makes sense.  Someone spacial is recommended for orthodontic work. Some people just are not spacial.  It can be hard to find the trifecta of awesomeness: attention to detail, spacially aware, and artistic.  Unfortunately, in my observation, the vast majority of orthodontists are none of these three.  A truely exceptional orthodontist is artsy fartsy.  They are sculptors.  They often are less prone to explain what they are doing...with a loss for words.  If an orthodontist is capable of breaking things down... it is because they mentally are rigid with certain ideas.  Experience helps.  Kind of matrixesque.  I have been in my highly detailed, technical profession for so long (over 10 years) that I don't really think things through logically any more as much as feel.  I already have a strong grasp technically, know the pitfalls, etc.  That is a good ortho for you.  The very good ones can explain to you what they are doing.  Those who excel cannot.  This is hard to distinguish, because there are those who do not explain and do not know.  Like a former in-law of mine.  He is spacially gifted.  He had made a spiral staircase for someone who taught at a University.  He made it to fit within an inch of the floor.  He had been asked what CAD program was used.  To the professor's astonishment, he replied that he didn't use any program.  Some of the most gifted cannot explain in understandable terms what they are doing, because there are many different factors.  These men tend to be somewhat effeminate, though not always.  The connection on women's brains are more established.  An artistic man or a technical woman is going to be a safe bet!

Here are 2.  The fan shaped one is to widen only the front.  It may be appropriate for someone with a V-shaped arch.  It can also be reversed the other way and fan forward for someone who is extremely parallel.  I personally like the control of the first posted above, though it is for more nuanced arch creation (ex.  The acrylic would likely break if pushed to extremes.)  Speaking of, I HIGHLY recommend 2 indentical devices.  If you lose one, you'd be shocked at how quickly relapse occurs!!!!!  By the time you go to get an impression and another device created, you are in a WORLD OF HURT!  Jaw pain, potential vision changes, etc.  You'll likely have to start all over as gains (even behavioral) evaporate.  You DON'T want to lose these!!!  I ALWAYS recommend two identical appliances and turning them at the same rate.  To get really good expansion, a lower appliance can be beneficial.  I don't see any acrylic ones I like.  They over-broaden the front, giving the appearance of a wide chin.  This may look good on guys?  Not so much for gals.  Here's the thing.  With saggital on kids, you're going to get tipping.  With adults, it's guaranteed.  I have noticed that tipping can be tamed by including lower expansion.  That is because as the top tips out, the bottom can cave in - in sync.  It's like a dance.  The bottom being kept from tipping in can assist the top from being tipped out.  I know this sounds strange, but I have seen this and saw a post on here with the same pattern.  The lower device that I like (fixed) is highly beloved by many local orthodontists.  It is unlike anything I have seen online.  I can get more details.  The bottom tends to follow the top a bit with young children (phase 1 age)... 7/8/9.  It will lock in gains better to expand the bottom.  There will be more relapse if only the lid is worked.  Additionally, the jaws you want in sync.  There is also the lid/jar analogy.  I personally get concerned when hearing about orthos only working the top... expecially past the age 10.  Of course,  bilateral crossbite and certain things may make sense for that.  I am not a doctor - merely passing along validated research and personal observations.

I don't love this forward movement one and prefer the FAGGA or something else that applies appropriate pressure to the front.  The Y shaped one I much prefer... but for someone who has a cliff for the arch when the mold is made... getting that front portion out may help?  It is highly problematic to flare teeth as the tongue likes to keep them that way.  That is what I heard from a local ortho and it makes sense.