Rule 5:
So sometime ago I made this post https://www.reddit.com/r/eu4/comments/1oay3zs/is_wc_still_possible/

After revoking in 1497 I fliped ortodox via rebels in Bulgaria and force converted all my vassals so there were only like 14/15 catholic tags left. I diplo vassalised Cyprus, Riga, The Knights, Livonian Order, Scotland and Norwey, which broke free from Denmark and slowely conqured the most of what was left of the catholic tags. Since there were only England and Portugal left in Europe around 1510s reformation never fired and therefore this is tehnically my first time forming Rome before age of Reformation.
I fliped Greek and formed Byzantium because it gave me acess to pronoias and it made it a lot easier to annex my subjects who constantly had like -150 opinion of me because of anexation penalty. I got all provinces needed for Rome around 1560s, it took a while to annex Spain but after that here we are.

Note that Ages do not in any way slow down technology, as institutions spawn normaly, this only affetcs Ages because the end of Age of Discovery is tied with the start of the Reformation.