The thing nobody mentions about free dating apps for couples for poly is how much of it is usable without a card.
About 100 profiles into the platform, the pattern around whether the free version is a demo or a product became obvious.
Unless you are in a major metro, expect what the free ceiling looks like in practice to be the limiting factor on that one.
The gap between good and bad platforms here is whether the algorithm is doing anything useful.
Photo quality moved my results on the site more than anything I wrote, more even than what you lose by never upgrading.