Great work, and nice to see you are making progress
Something you can try to be 100% sure that it is a weight issue is to see that your servo in fact can move further with the lid disconnected (just remove the bolt that is connecting the brass / anodized servo horn to the wood linkage.
The reason for this is that from watching the video I'm not entirely sure if the lid stops when it has past the point where it's the heaviest, or just after.
(When I think about it, you don't have to unscrew anything. Just point the scope at the zenith. If it fails to move at all or if it opens to the expected position, it's the weight for sure).
However it might be servo centering. When you hear the bussing at the most open position, and it stops to move then it is binding.
There is three ways a servo can bind.
1. The object that is being actuated reaches a mecanical endpoint, and can move no further.
2. The object being moved is to heavy and the servo motor is skipping.
3. Internal binding.
If the weight test above do not proove it's the weight (i.e servo motor skipping) then it's allmost certanly internal binding.
Servos work at a PWM pulse from 0.5 - 2.5, at least some of them! There is no standard that ceeps a servo from actually woriking in PWM range 1.0 - 2 as an example.
If you tell a servo to go to PWM 0.5, and it has internal limits at 1, then the servo will appear to bind, even if it is not binding at an endpoint or skipping from overload.
If you have not done so allready, you can disconnect the servo horn completely, and try to Park / Unpark while encreasing / decreasing the (Max travel limits [set open travel (ms), set close travel (ms)]) in the Calibrate tab. You should aim for the limits closest to 0 and 3 that you can acchieve while the servo makes no sound at the endpoints. You should do this while the (Preffered travel limits [set open limit (%), set close limit (%)]) is set to 100, 100
After that set your close limit to 90 - 95%, park the cap and attach your servo horn and linkage while the lid is closed against the telescope. (Then you have 10 - 5 % to work on when the lid is connected to the servo, to ensure that it can close fully). Leave your preferred open limit at 100%, as it does not look like your setup will bind.
Hopes this helps to determen if you need new servo / lighter lid, or if you can calibrate it out, (not sure if I explaned thiswell enough on the github readme, so tought I'll go into some detail
)