It's not smart cheerleading just because a lot of gyms do it. It's not ok for a back to throw under a butt or from the ankles. The back belongs under the toss. That is the only location for the back's hands that allows them to mechanically increase height on the toss.
If you have a flyer who is having trouble standing up aggressively, teach them to stand up quickly. Don't use the back as a means to Band-Aid the flyer's poor technique.
If you have a flyer who is having trouble keeping her feet together, rolling off the bases hands (whatever that means), or twisting, teach the flyer to do those things correctly. Don't use the back as a means to Band-Aid the flyer's poor technique.
If the bases are breaking too low, or are too slow off the bottom, they need to learn to throw correctly before you add the tossing assistance from the back or a front. Don't use the back as a means to Band-Aid their poor technique.
Ask a flyer doing double baskets if she wants anyone doing anything with her toes. If she doesn't slap the taste out of your mouth and tell you all she needs is the added height from those people throwing straight up the way they are supposed to throw, then she SUCKS at double baskets. She has no business doing them.
All of the things you just described are a means of cheating stunts to make up for poorly taught skills and poor technique.
edited to fix a typo
Who says the back belongs where? Technique, as it is currently defined by the governing bodies of cheer, allows the back to throw from either location. Aiding the flyer in maintaining a more successful body position isn't a band-aid, its smart coaching. Whatever makes the team more successful and safer isn't a band-aid, it's coaching in a way that ensures the safety and strength of your team as a whole.
I never said I don't work with my bases and flyers on their technique, I just said I use the backspot to assist the bases/flyer with the parts of their basket that may not be technically perfect in order to ensure that the basket they throw is as powerful and safe as possible.
Technique, in any sport, is decided by the governing bodies based on the needs of the sport (thing cheer tuck technique wrapping behind knees and gymnastics technique wrapping over). Until USASF/Varsity say that it is bad technique to throw from butt, than it is not bad technique to throw from butt. I have been to NCA and UCA camps where the instructors allow the back to throw from wherever they want because the technique score comes, not from where the backspot throws from, but from the height of the basket, the speed of the bases and when they break, and the body position and shape of the flyer.
As to the note about the flyer having her toes thrown, you're just wrong. Many of the best teams in the entire world throw from the front to speed up flyers toes to get them through to the cradle, not because it's bad technique but because it's more efficient.
I have thrown double baskets, pike open doubles, x fulls, front doubles, arabian fulls, arabian one and a halfs, and kick forward fulls. None of the flyers slapped me and told me the front spot was useless, because it is a common accepted practice in the sport and makes their baskets more successful.
The two NCA national championships my school took home weren't hindered by the front spots either.
Heres team USA having the front spots throw toes to get the flyer through to a cradle:
In acro gymnastics and circus acrobatics (which I have also coached), who created the technique for basket tosses in the first place, when you have three throwers they actually put the third in front, not in back. They believe it is bad technique for the flyer to require someone behind her to catch her, that she should be able to do that on her own. For those sports it is more important to have someone pushing the toes to ensure that the flyer gets through to the cradle. So even historically it is technically correct.
Heres the Combined routine in mens 4 four Belgium as an example:
So is having a backspot on baskets at all bad technique? Acro gymnasts would say yes, but the reality is technique for the same skill can be different between different sports, and that it is up to the governing bodies and judges to define what good technique even is. A good example of that is the ideal head position for tumbling. In TNT they want the head out in whips and they teach their tumblers not to press their arms. In artistic, they teach a neutral head position and encourage their tumblers to press their arms. In acro, they want layouts to have open shoulders to get a more "artsy" floaty dance shape. I cheer, we encourage tumblers to have their layouts be slightly more hollow than in gymnastics with a more open set.
Technique can be different between sports and teams for the same skill, while still being technically correct.
Until a judge drops my basket score because my backs are at ankles or butt, I will leave them there. For now at least, moving my back spots to those positions raised my basket score because it enabled the flyer/bases to do their job, which is actually being judged, better than it was being done before before.