I can see the utility, but: > Small fee because i am writing very rarely there like the problem: I don't think the number is people willing to pay that small

I can see the utility, but: > Small fee because i am writing very rarely there like the problem: I don't think the number is people willing to pay that small fee is worth it from a commercial perspective. Of course you might get lucky and find a f/oss option written by someone with very similar needs/wants, but you'll probably have to self-host that so have a bit of admin to do.