The non-Mini version was such a hassle to maintain¹ that I stopped using it². This looked like a great middle ground, until the subscription part.
¹ I don’t want to become a networking expert and babysit everything. I already practice good security regarding what I install and run, I just want a little more control.
² And if it was a bother for me, there’s zero chance any of my non-technical friends would last an hour.
I forget what it's called but there's a mode you can put Little Snitch into that it allows whatever goes through and you can monitor it by opening and reviewing when you want. I think that's fairly similar to what mini does. This turns off all the nagging.
This is actually what I did last time I used Little Snitch, it helped a lot. When I installed a new app I'd use it for a bit, then review in LS and see what it was doing. From there I could allow or disallow whatever I needed.
It's sort of the reverse of "block everything until allowed"
Several apps on the Mac App Store have both subscription and lifetime pricing. I’ve bought several.