I think it would not hurt. We already have a 'request per period limit' to be kind to metadata servers.
Inferred from a few posts I have seen, some folk appear to think that they will get better (metadata content) if the regularly repeat downloading for their library

(I expect Calibre will get the same responses in most cases.)
The only time I DO expect a
better result is for a SINGLE just released book.
So setting a limit, just helps doing our part to be a good network citizen, even if it would be a small blip in the overall traffic.