So.. I'm not entirely the most reliable source to comment on this but here's my two cents.
The indefinite bans list is pretty much just a text page containing the answer to question 1 to the indefinite bans request for the player with a link to the request page on the forum. Presumably, although I haven't seen it myself, a players entry is completely deleted if and when an appeal is approved, as I don't see a list of IPs being indefinitely banned without an account tied to them.
But I'm also not entirely sure if the indefbans list that admins can see is just for log purposes or if the server actually uses that list to keep players banned on the server, so take that with a grain of salt.
But from a quick CTRL F of the list, there are 170 banned players and around 800 banned IP addresses. 1 player has 22 IP addresses linked to his profile alone and I see several other people with 10+. Naming no names here though.
My best guess is that question 6 primarily exists as just a means to ensure that the player cannot be banned by any means, maybe a console /unban (IP) is done when removing the ban to ensure they're cleared out. I'm just speculating here with what I have.
Still, that begs the question of whether or not we should be pruning IP addresses or not, especially as the ban bypassing ones are almost always VPNs