It takes alot to make it stay in one place.
Pure motionless hovering happens to be one of the most difficult things to do. The aircraft drifts with the air which is -always- in motion.
A little jerky and it like to move by itself.
Jerky when -you- give it commands, or by itself? If by your command then add expo. Or use more finesse to give smaller smoother motions to the sticks.
Can you tune these without TxPID or OPlink?
Tune 'what? Hovering? As has been mentioned only GPS can do that.
Tuning generally refers to 'motion' flying not standing still.
I answered my own questions I am tuning it currently in my living room.
Is this related to the above where you said 'takes alot to make it stay in one place?' If yes then indoors the quad will *NEVER* hover properly easily. The downwards air blast from the props hits the floor, travels across to the walls, slides up the walls to the ceiling, and travels to the center where it turns downward to feed the props more air. The quad creates its own turbulence.
There's even a 'wall magnet' effect where the closer you get to a wall it feels like the wall is sucking it in. That's related to the outdoor 'tree magnet' effect which is a -real- aerodynamic effect. Air is a fluid medium whose motion we can't see but can see and feel the effects.