So i finally had 5 hours of sparetime until the sun went down to get at least some packs airtime after two weeks off.
With my 5 inches currently grounded and waiting for parts and maintenance, i decided to build this 3 inch out of the parts i had around and fitted that nice BQE frame. Did not care too much about weight.

Maidened it with some 3S 1500mah and 1300mah from my big quads. Flys already really good on stock BF pids and rates, dynamic filtering on, flashed ESC to latest blheli 16.7. Flight time of over 4 minutes with acro moves and almost fullspeed. Had to adjust my throttle management, due to the heavy battery, specially coming out of dives, but it works, wasn't expecting that.

Second packs i tested were 500mah 3S, probably too low, flight time went really low, probably cruising will be fine.

Still haven't figured out if i'll go top or bottom mount, works both ways atm.

Also needs some finishing touches, better antenna mounting and whatnot.

Well do more testing and tuning next week, probably add some flight footage.

update:
third day of real flying and testing battery sizes.
changed props to racekraft
nice and agile with 500mah 3s, still carries gopro with 1300mah, but only tested on stable mode :), need to test 4s 800mah, thanks for the tip to BQE :)

footage with 3s 500mah lihv

update 2:
finally had time to test how it would behave with a gopro session 5 mounted using 1300mah 3s here, sorry for the camera angle, next test will be 800mah 4s and appropriate gopro mount ;)

update 3:
fixed the gopro mounting a bit, still waiting for the 4S to arrive.

update 4:
4S 850mah is a blast, and still ok to handle with a session 5 ontop

update 5:
still rocking solid, got quite comfortable, even with gopro mounted. also took some crashes without any substantial damage.