My recommendation is to do calculus 1, it is far less of an inconvenience than spesh ( i would recommend you do spesh only if you are aiming 99.95 from your position), and especially because you enjoy the other subjects.
Calculus 1 could be considered more of an accelerated pathway as you only acquire basis for Calc 2 and linear alg. In spesh, you do stuff that is interesting but not all required for Calc 2 and linear alg (there is a lot of overlap between spesh and these two uni subjects). Mind you, i.m going on very little experience here. I've seen calculus 1 question book from UoM and its content is very skills based, very little application (don't kno if u do more than what i saw), and there's probably way less stuff to get through than spesh.
So, you have a good basis for maths from VCE (further and methods), and breadth with chem and phys, especially for science in uni is great, so i reccommend doing calc 1 and leaving out spesh atm.
Ultimately the decision is up to u, just keep in mind that 99.95 point, that's really up to you .
Good luck!
