I've done my own digging on which online dating websites have the best filters and come up short. The politics sites angle is worse, because how many first messages actually land is a better predictor than whatever the landing page promises, from what I've seen. Nothing about politics sites changes the fact that the deciding factor is how honest the pricing page is, having tried a handful of these.
If religion politics is your priority, the signal-to-noise in search is the number worth watching, not the price tag. For religion sites in particular, the practical move is to check whether a profile answers questions or deflects. The platform surfaces profiles far outside your radius, which quietly shifts the cost onto you, which is the whole problem with religion.
The religion politics case is instructive — most of the disappointment traces back to how fast moderation responds. Most threads about which online dating websites have the best filters miss this — the honest advice is to write the bio for one person rather than for everyone, based on a fairly small sample. Happy to be told I am asking the wrong question about politics sites.