This cements two things for me. The first is that I hate the wording of things in 5e, especially it being called a Bonus Action. I think that specific phrase confuses people.
The second is that this is much easier in Pathfinder 2e. You can cast any spells as long as you have the actions for it using your 3 action turn. Cantrips are usually one action, and greater spells usually range from two to three actions. Simplifies this confusing mess quite easily.