OSD: show PIDFF Errors to be able to tune a quad better in flight

[Pairan]

Current Behavior

Currently tuning the PIDFFs on a 7" is not that easy (for a wing pilot like me). I need to launch, fly, record in HD and compare the results which is somewhat time consuming. And to know where to tweak it, I will have to use the Blackbox explorer.

Desired Behavior and suggested

it would be cool to have some OSD values after which I could tweak Pitch/Roll/Yaw according to the PIDFF Errors ... minimising those would make it possible to get a smooth ride :)

Who does this impact? Who is this for?

Wing pilots like me who also want to INAV their quads to get the Unicorn magic! :)

Additional context

Perhaps I'm totally uninformed about what's the best way to tune a 7"er with INAV so I try to stick to what I know and perhaps can handle. I find it rather hard to tune quads with INAV currently. So if anybody has an idea on how to make this all happen, I'll surely be listening! (and yes, I watched all the Pawel videos about the 7"ers ... but as by now an so many updates on INAV the most used magic seams outdated)