Hi Simba,
why don’t you just try it out? Maybe with a smallish project.
I used 1000 just today and it worked - kind off because it does screw up everything else and so it doesn’t really help much.
In my experience there is a problem with alignment if the GCP is not where it’s supposed to be. When I started out I often had errors of several mm (with buildings surveys), but since I know how to do it properly the errors went down by a factor of 10.
I noticed that trying to force RC to do something it doesn’t want to (it’s stubborn like that), won’t really get you what you want. Not too long ago, with my good alignment technique, I had one point that would not work never mind what I did. I almost gave up on it. Until I realized, that RC wants to place the GCP exactly 1 cm lower than the measured coordinates of the point. Then it dawned on me: I sometimes use a tool when I want to measure points on the floor that are far away, which is not possible directly. It’s basically a vertical face with a point 1 cm higher than the ground. So obviously I forgot to adjust the coordinates accoringly and RC was right on the spot! That really convinced me of the incredible accuracy that is possible with RC…