I like your solution because it physically prevents the power button from being pushed. The important thing here is not removing before flight, but removing before power up for ANY reason!
Back in the day when I was flying, I was religious about using checklists, but this is a case where a checklist won’t always protect you - powering up to access data on the drone is so simple that nobody is likely to create a one item checklist. It’s like a gust lock on a plane with a pin that goes through the yoke shaft, so you can’t move the yoke in any direction, until you remove it.
DJI should change the gimbal lock design to include a tab that covers the power button...and give you a royalty for using your idea!