I think it is impractical to study something that won't contribute directly to your study score/ATAR. You have holidays, after you finish year 12 (a long 3 or so months) to engage with the content in SM.
Realistically you only have one shot at this (VCE) so keep focusing on the subjects that will make a difference.
Right now I spend about 3 hours every night on spec trying to catch up to the class.
Catching up in a class that has no weighting on your ATAR/study scores.... it doesn't make sense. These 3 hours could be trying to improve English (as an example). You would be better off putting these 3 hours to methods if you still want to keep it math-related.
I've been slightly disheartened because nearly all the reactions I've received from friends and family are negative.
Of course what you do is up to you.... and I get you enjoy it.... but you need to be realistic.
I think your remaining time should be spend relaxing, leisure activities etc. If you study all the time, how can you de-stress and be in the best state of mind?
So in terms of "is it worth it".. i'd say no, given your current context.
Just my thoughts.