I’ve had the same decision to make.
In general my thinking has been that if I only have a male of one species and a female of another, then why not try. Essentially it will be hybrids palms produced or nothing. There’s not really any cost to doing it if it doesn’t replace pure species.
For example, I have a lonely Chamaedorea woodsoniana male. I have a Chamaedorea costaricana, oblongata and hooperiana females but no males of those species. I’ve been hand pollinating just to learn what works with what. I have 3 male Chamaedorea klotzschiana and a female so I don’t include these in any experiments and instead focus on isolating to produce pure seed.
Perhaps if any of the species in consideration were critically endangered then maybe there’s a deeper debate, especially if the endangered palm is female and it’s worth trying to source male pollen somehow even internationally to continue the pure genetics. But in this case R glauca Isalo are spread around the globe fairly well and in no immediate danger so I don’t see what harm its doing by trying. Ravenea have been known to hybridise so you might end up with something interesting that inspires new collectors who ultimately contribute to palm conservation. I’m thinking of Tribears, Mules etc being introductory palms for people who then go on to become serious collectors and conservationists.
That’s just my 2 cents on the topic but I’m happy to hear everyone else thought as it is a controversial topic for which I’ve heard arguments on both sides.