Hey stat, I'm in a similar experience position to you, have been using a Naish custom global with straps a few times, my twintip transitions are usually ok and i can ride toe-side natural but not goofy. I've found the surfboard straps useful when my transition doesn't go to plan, both to grab onto if changing board direction and to keep my feet attached when I'm stalled in the break, I can't yet transition on the surfboard by changing feet but that's the next progression.
I say give it a go whichever way you can (afford or physically achieve depends which is your limit!) then find what works for you and progress it.
Have fun, cheers
j