It’s hard to make an internal switch from liti to corp after a few years of practice. The reason is a practical one - you’ll be a complete noob when you move from liti to corp, and there’s little business case for them to allow you to do the switch. That said, it has been done before, but you’ll really need to be able to convince your partner to allow you to do so. Otherwise, just change firm and change practice area. You might get a PQE cut but that’s that.