Is this the base that comes with the Romeo5 or did you get an aftermarket one?
If its the standard one, you should be well within a margin of error where any differences are just as likely user induced. This is especially true if as @Gary_H said, you are consistent with how you mount (press it forward). Maybe its not exactly 100%, but its like 99.9999999999999% Once locked in there should be no wobble side to side, front to back, or up and down.
I think your plan of waiting until the next range trip before unmounting, loctiting (is that a word?), and remounting is solid. You are then just confirming zero, should only require a few rounds for peace of mind.
If it’s a 3rd party mount, then “it depends”. Some are really good about return-to-zero and others aren’t. Cheap QD mounts are notorious for losing zero. High-end QD mounts or non-QD mounts are usually pretty good about keeping zero.
How are you liking the Romeo5 so far?