Here is an example from my game. I hit a lot of dtl FHs. I tend to hit less ts on dtl than cc (both wings). Sometimes I am targeting shorter (service line ... just past), sometimes trying to hit deeper. That is almost all swing speed in my case, because I am not thinking higher/lower over the net (who knows what actually happens subconsciously ... and I have no record of actual net clearance), and I am not hitting shorter with more spin.
coincidentally i was thinking about this problem myself this weekend... particularly on the bh side... (my opponents often camp in the bh side because they anticipate my favorite inside out or dtl fh to their bh)
what i was thinking,... is that because i have a make contact a bit later (on the 2hbh) to go down the line (therefore less "runway" to generate rhs), i need to exaggerate how much of the rhs goes to topspin (vs. driving the ball).
seemed to help me make the shot more consistently
I guess thinking about it ... three main ways to control depth/targeting:
1) swing speed
2) spin
3) net clearance
agreed
Add to that if I have missed something obvious ... maybe racquet face for some advanced players.
Let's use my wife as a more representative example of adult rec tennis than most of us on this forum. She started playing tennis mid-30s. She played years of 3.5 women's USTA doubles ... went to Nationals once (she would have been 4.0 if she ever played doubles 2-3 times a week). So I have watched a lot of 3.5 ladies 3.5 doubles, and I can't remember one topspin stroke. Surely there were a few, but I can't remember any. You would on occasion see slice (ugly version of it

). So guess what it looks like when you have 4 non-ts, non-lag ladies at the net with mini. The average men's USTA player doesn't look much better stroke wise, even if they move better.
I agree logically the bigger the lag, the better chance for max relaxed arm (at least at start of swing ... seems like measuring at flip into contact might surprise some ... but we can't measure it. I don't think the degree of "arm relaxation" difference in a "decent" stroke is really the issue with mini. For example, you hit big fh lag (I have a pic of that NYTA lag ... impressive). I experimented with flip and bigger lag, and it wasn't for me. Zero lag also wasn't for me ... I had migrated from traditional back fence front fence fh to modern adjacent.

Basically ... a see some lag (not sure what qualifies as small flip) in my fh.
agreed, you defintiely don't need topspin to play tennis (as 3.5's across the nation will attest to).
[warning long monologue]
even with stiff wrist, no lag, you still need to know how to brush the back of the ball... (try conti grip fh, with no lag/drop/flip - though generally there is some)
issue, is that most rec folks (3.5 and lower) need a "large" contact window... so they point the face at the contact zone, and keep the face "square" to the contact the entire time... ie. that's the reason folks have a waiter tray serve... they open their racquet face the entire time to insure they make good contact even if late or early.
problem with brushing... or in the extreme case lag&snap'ing... you are intentionally reducing how long the face is in contact window in exchange for more spin
imagine a ball travelling horizontally (ignore spin, arc, etc...) i picture my "contact window" as a ~1ft long x 6in wide/high rectangular prism... the bunter will keep their face sqare to the prism... 2-3ft *before* and through the prism... increases the chance of making solid contact... (but no spin); the topspinner, will attack the prism vertically from the bottom which obviously makes making contact more challenging (in exchange for spin)
alternative mental model.... imagine 3 cars... car1 moving south, and car2 moving north in a headon collision toward car1.... and car3 moving perpedicular towards an intersection that may/may not collide with car1... which is easier to time? (the perpendicular intersection can be varying degrees from 1 to 90 simulating the amount of brush various strokes can have)
so mini trains me to sync the timing/feel of the brushing (attacking the prism from the bottom) using varying lengths of backswings
so if i wasn't interested in practicing "the brush" for topspin (and instead hit flat or backspin),... i'd probably avoid mini as well...