This is a common problem form Lipo and Li battreis. When the shelf time is so long - the battery Voltage drops and it means the resistance goes very high. So there is a risk of fire if the power pass by upon connecting it to a power supply. Therefore, the little Capacitor behind the unit blocks all the current. I think Ledger changed this in the new firmware. So the tolerance is much more than before - and battery can charge now easier.
I must say I hear much less these days that this problem happens. And if a device has a problem, without changing the battery, I simply upgrade the firmware and problem simply gets solved.
Again, I am (somehow) expert on this, and I can imagine not everybody is familiar to do it.
I am not a technician, so I can't comment on whether or not your fix is good enough. What I can say is that Ledger obviously made physical (hardware) changes to their new black box version of the Nano X in the areas around the battery and connectors. So I don't think the problem can be fixed with just a firmware upgrade. I must say I hear much less these days that this problem happens. And if a device has a problem, without changing the battery, I simply upgrade the firmware and problem simply gets solved.
Again, I am (somehow) expert on this, and I can imagine not everybody is familiar to do it.
If you have so much experience in fixing these devices and are confident your solution works, make a video of a faulty device that you fixed in the way you explained it. Post it here so we can watch and send it to Ledger as well. Who knows, there might even be a reward for you if they like it.
Sounds like a good idea. I will make the video first. Post it on youtube and share it wit you guys...give me like 10 days...I will work it out!