So the way Riot does bans for 3rd party programs is that they do them in waves. I know it sucks that third party program cheaters keep playing but don't worry, they will get their comeuppance.
This is to prevent the programmers from understanding how their program was detected. The more frequently a person gets banned using a program, the more chances the programmer has to figure out how their program was detected.
It's trial and error. This is their player behavior model for the ban wave method:
Programmer tries A in their script, it got detected and banned. They try B, it got detected and banned.... etc... they try D, not detected and not banned! Hooray the programmer has found an exploit! A few weeks go by and no one is getting banned!
I'm going to buy the third party software because it's not detectable and I'm going to cheat!
VS
Programmer tries A... not sure if it worked or not.... a few months in, everyone who used it got banned. Programmer tries B.... not sure if it worked or not... in a few months, everyone who used it got banned.
Ugh, it takes too long to figure out if people who use third party software will be safe... I'd rather not risk using the third party program.