I see your point and of course it's better to do so. My point of this topic was above all to understand what was going on and if RClone was handling these errors in the right way.
Apart from the latter, I think it is really strange that a snapshot has those files presented with a size of 0, while that's not the case when copied. I can understand that when copying from the actual source, as those files are in use by the Chromium processes, but not from the snapshot.
As for RClone's handling, I didn't know when I started the topic that these files are actually listed with file size 0 (or in some cases 8 bytes) in the snapshot. That's why I wanted to know more about this behavior.