I've been meaning to try those Twiggy Futures - keep us posted on how they go over the winter.
It's definitely a good thing, tweaking fins, but steer clear of changing them every session - like surfboards, sometimes it can take a few sessions to really suss out what's going on and how to make the most of it.
If you are lucky enough to surf most days, then you can form a picture of what works well in which condition/size. If you surf less frequently, then there is some merit in leaving it all alone for extended periods and learning to surf what's under your feet.
The reasons pros don't moan about fin choices is predominantly because they take the time to really suss out what works well with each board (with the benefit of the person who shaped that board chipping in with their thoughts as well) then they stick with it, gently tweaking the formula here and there on their 'main' boards.
Far too many options these days... sometimes it's good, but other times I see people who are still learning who have full-on quivers (as that's what they feel is going to help them progress) and their enjoyment is often hampered by being hung-up on equipment choices
But yeah, as a rule-of-thumb, the same fin template in a better material isn't going to be too detrimental to your surfing.