RF800 and crop sensor cameras

I'm one of those who has been waiting what seems a long time for Canon to bring out a crop sensor in the R space, and with the R7 and R10 announced I got to think about the RF800 lens. I've been a crop shooter for a number of years, using the 100-400mk2 on several bodies.

Currently I shoot birds and wildlife, normally when the light is good, and having the extra reach on crop appeals a lot. I then wondered about the RF800 and how well its going to work as with the 1.6x crop and if its actually going to be too far a reach to manage hand held, even with IS to keep the lens easily on target - not to mention environmental considerations like heat haze and pollution etc.

So I then wondered about the RF600 and then wondered if that might be a better option for extra reach and possible a better chance at keeping it on target.

Then I wondered if a 1.4x extender onto my lens would be a better option but as it will have the RF adaptor on, i then worried about if that was a good idea and finally got myself into a position that I just don't know what to do and end up just going back and forth between options and getting no where,

I know that that all the options will have an image quality cost and am comfortable for that as a lot of my photos are for reference / tracking  or identifying individual birds by their markings which the extra reach helps with.

I'd appreciate some fresh thoughts to kick me loose from this which I should buy loop.

Thank you for reading to the end.