I think I found the flag and discussion that you’re referring to, but even if I have the wrong one, the points below should still be valid.
iNat guidance on requests for new taxa does recommend that curators add taxa that are requested individually (rather than a large batch) and only where there are iNat observations on iNat. I’m pretty sure the curator’s request for details of observations was based on trying to follow that policy.
Similarly, I would be fairly confident that the curator declined to add that one name simply because there wasn’t an observation for it and so it didn’t meet the guidance. Opinions vary on this, and personally I don’t see much reason to wait until there is an observation before a taxon is added. I think this is something of a relic of iNat’s early days, although I might not be enthusiastic about adding dozens of species for which there are no plausible observations simply because someone found them in a checklist.
It seems very unlikely that the curator intentionally added IDs to the observations you listed in order to claim some kind of priority. Much more likely, after putting a little time into looking at POWO and other sources to validate adding the new taxa, they felt it would be useful to add IDs for the relevant observations, without any intention to “scoop” your own IDs. If my assumption is correct about the iNat user involved, then I’m pretty certain there was no ill intent, as I have worked cordially with them on a bunch of taxa over several years.
As others have said, it’s really important to assume that others mean well. We all come across perplexing actions on iNat, and while a few of them may really be bad behavior, many more of them are just misunderstandings, especially at this level of detail.
If you feel it’s important to have your name on the first ID for these observations so that it shows up on GBIF, I guess you could ask the curator whether they would withdraw their IDs and then re-add them. That probably wouldn’t be important to me, but I also wouldn’t have a problem accommodating that request from someone else.
It’s great that you’re interested in tackling the taxonomy of plants on Hispaniola and I wonder whether it might be more efficient to do that as a curator yourself? Of course, there are a bunch of policies and rules that we curators have to abide by, but if you feel you can accept those, you might want to request curator access. That might make a lot more sense than making flags to request others to add many taxa. I would caution that curators definitely need to take a collaborative approach, but if you accept that, then iNat could benefit from your contributions.