so anyway ive been fighting this for like three weeks now and im at the point where im genuinely considering just buying a prebuilt and calling it a day. the quad flies fine at low throttle, feels pretty smooth actually, but the second i punch it i get this horrible propwash on the way down, its like the quad just loses its mind trying to settle. already tried lowering P terms across the board, bumped D a bit, played with the filtering and if anything that made it worse.

running 2306 2450kv on 4s, 45A ESC, Dshot600, BF 4.3. props are HQ 5x4x3. the frame is a stretched X if that matters. honestly not even sure what other info is useful here, just hoping someone has seen this before because i cant find a tune that fixes it

stretched X frames can be a bit of a pain with propwash specifically because of the geometry, the rear motors are in a different wash zone than a true X and it messes with how the PID loop recovers. first thing id check is whether your RPM filter is actually on and working ? go into the motors tab and make sure your motor poles are set correctly because if thats wrong your RPM filter is basically doing nothing and youll have noise all over your D term. also 2450kv on 4s with 5x4x3 triblades is going to generate a lot of noise, some people have better luck dropping to a biblde on punchier setups but thats more of a last resort thing.

what does your blackbox look like? if youre not logging you really should be, its impossible to tune blind and you can see exactly where the instability is coming from. gyro trace vs setpoint trace will tell you a lot.

i had almost exactly this and it turned out one of my motors had a slightly bent shaft that i hadnt noticed. wobble was so small i dismissed it but it was feeding noise into the whole system. worth spinning each motor by hand with props off and feeling for any roughness, sounds dumb but saved me a lot of time eventually