I probably wouldnt slot it into every Commander deck I have, but I can see an argument for it in more than half of them
He gives every instant and sorcery in your graveyard flashbackand if its a Lesson, it only costs one mana
Rattlechains is one such good example, though there are certainly others
Its a natural inclusion for any build revolving around the fiery pyromancer and adds consistency without needing tons of setup
You need to be doing something beyond what's written on the tin, whether that's untapping artifacts, proliferating charge counters, or benefitting from card draw in some way, but put in just an ounce of extra work and the Engine gets a-rolling
Its best to play it later in the game and follow it with another elf + draw a card, or if you already have a good board to attack, otherwise you probably wont untap with it