[smeej]

Practically every church I've been to in the last 15 years has had an online giving option, and most of them use different platforms from each other, even though all the churches have been Catholic and many of them have been in the same diocese (where you might expect a "best practice" or economy-of-scale-type agreement to have been made that would lead them all to use the same one).

This is very widely done already.