Fixing the tripcode algorithm to make it approach something one might consider secure is all on the 8chan server administrators, not the people calling themselves Qanon. It’s not something the Qanon people can fix by changing their password or something. The fact that Q is relying on the insecure tripcode algorithm is pretty bad.
Has to work with the tools given. So far, seems to have resisted attacks well enough to maintain control of the message.
It's not as though the message contains the national jewels or anything. After all, if, as you insist, Q is a larp, what's that harm is working with a website that, like FR, has crap for security?