Im getting a fluctuating low side. Here is video of the system running, sorry for the bad quality, I was trying to give it some throttle while recording. Temp outside is 85 with 21% humidity now.
The system is still low. See how fast the compressor is cycling? It needs more refrigerant.
...and as for the "50/250" rule, I've used that all my life charging R12. 134 takes more pressure on the high side. It usually ends up "somewhere" around 30/300. All dependent on ambient temperature and humidity and "all that". If it's a real hot and humid day, I've seen 134 pressure reach out and touch 375 "or so".