I do get to decide what I am going to talk about, yes, and if that’s on-topic for the thread then that’s OK.
Of course you get to decide what you wish to discuss. And your choice is revealing as well.
As is your decision that the topic of the thread is “the treatment of the faithful who protested the heresy of the RCC regarding indulgences.”
I think that a bit of a personal twist in your discussion.
When do you discuss Luther’s heresy according to your authority? I’m assuming never.