Not that most players on NL50 are going to play near GTO (myself mostly playing Nl25, so not a huge difference i expect), but working with solvers will improve your game by a lot even without villains that are capable of playing GTO.
MY approach would be: Learn GTO-principles with solvers and deviate from it frequently. Exploitation and GTO dont work strictly against each other.
But i would recommend you to check out GTO+ instead of PIO: Its much cheaper and offers a play against the solution mode which is just awesome for training purposes.
Feel free to PM if you need any help with this tool or solves.
Cheers

The things that help me beat a (soft) NL 50:

posting hands and talking about them with my brother
getting flopzilla pro and thinking about villain ranges from street to street.
GTO+, which integrates nicely into flopzilla pro. The whole thing costs like 0.25 PIOs.

Pretty sure you are doing plenty of mistakes as most poker players do(me too). So need to find areas where are you doing them. Coach, study partners, your own fundemantal knoweledge will help finding those.
Next is to fix/tweak/improve them

Every position stats

Consider hiring a coach if you can afford it.
Would also recommend lucidgto if you want to get more into GTO. Or consider transition into PLO ;)

You cant beat poker without studying anymore. Clicking buttons for 200k hands is useless, save 100k hands and spend that time studying. I don't think its possible to move up stakes unless you spend 1:1 ratio of playing and studying. At 50nl you are the fish.