I support it. If it's the only basket you have, working on that one is certainly better than working on no basket at all. Yes, a part of muscle memory is accustoming oneself to the proper amount of force it may take to knock down, say, a 15 foot jumper and that force could differ from playing on a 10 foot rim in comparison to playing on a rim bent down to 9'8'', but that's only part of the equation.
A bent rim can still provide ample opportunity to work on just about every other part of your game. As mentioned, the strength memory may be thrown slightly askew, but making that adjustment (once you're back on a true 10ft. bucket) will likely be easier than many like to think it'd be. Also, a bent rim would still allow you to work and practice the correct shooting form.
In truth, most outdoor rims out there (and even many indoor rims) are not precisely 10ft. The outdoor buckets I play on vary from being a bit below 10ft. to being a little bit above 10ft. And in the end, once I get back into a gym (with a true 10 foot goal) there's a bit of an adjustment I have to make at first, but everything seems to fall in line pretty well once I warm up.
Thanks, I see. The rim I'm talking about is bent downwards. It's easier to shoot from straightawa on it than with other rims, on the other hand shots from sideways are much tougher to hit because if you don't swish them they'll pretty much bounce out half the time due to the weird angle.