Fortunately my very ex company didnīt ask to do any other maintenance outside than normal line checks or some unscheduled repairs during flight day. (A.O.G)
A-check is usually too "big" to perform outside, too much noise-possible rain/wind-lighting issues. Tooling and equipments need to be carried...
Not even on sunniest mid summer day.
My strong opinion is: all planned maintenance should be carried in hangar, line checks and some smaller limited works can be done outside. (wheel change etc etc)
Doing work outside you always risk work quality just for unnecessary distractions etc etc
Bright sun is not best working light, or dark night just with headlamp and ramp lighting either.
Been working for company which hangar was too small for all incoming planned works, and getting aircraft from apron to hangar was/is silly complicated due to stupid airport layout and too busy??? ground handling. We did lots of work outside and i never understand how it can be ok for monsters EASA / CAA UK.
Hangar for maintenance, apron for parking or flight operations, heliolatry for days off.