luckily me and CD have created the literal only reliable TF feat thread online
https://onelastforum.com/threads/transformers-feats-discussion.71/ tl;dr
Alternity=higher dimensional evolved transformers that are bigger than universes, there's an iffy statement about them affecting every workd, and Megatron in this form shook tons of universes just in his death throes
13= first transformers, cosmic quantum clusterfuck higher dimensional beings. By obd standards they are megaversal to megaverse+ from Vector being able to stop universal clusters from being destroyed and Solus shattering the star saber. Cosmology wise transformers is a (very) small omniverse by obd terms, and the star saber can destroy it so their leader Prima is on another level
Unicron and Primus predate the cosmos and are actually operating in weakened forms for 99% of the stories... where they can still affect the entire multiverse regardless. True/Astral Unicron would be the main top tier as he's much stronger than any of his physical forms that have threatened the multiverse and the overpowered Primus in their first fight, but Primus ultimately crippled him which is why everyone isn't dead now.