Stock values work very well. Leave them stock.
Some other things I can think of are:
- power: if there is not enough power, then there will not be enough control. Power can be limited by battery too small or old or not charged, motor too small, props too small or too large.
- input page settings not correct: settings that do not let the stick full motion come through
- output page settings: min should stop motor, neutral should have motors very slow, max should be full power
- ESC calibration: badly calibrated ESCs (even just one ESC) will not let a motor run to full power, and the other motors will be reduced to keep it level
I would calibrate ESCs, including setting motor min, max, and neutrals:
https://librepilot.atlassian.net/wiki/spaces/LPDOC/pages/12058743/ESC+CalibrationI would re-run the transmitter wizard (Input page).
If the model is small enough, I would put a coat and glove on for arm and hand protection, and use the Output page Test Outputs to test one motor at a time to make sure that the motors can produce full power.