Michelle, others on this Forum have suggested (politely) that I’m an idealist, and whilst that may be factual, I do admit to being someone who actively seeks a compromise that’s both equitable, sustainable, and in accordance with Strata Law.
That being my objective, I’ll suggest to you that even though your O/C may well be entirely responsible for the maintenance and repair of the sunshades by virtue of the fact that they’re part of the original construction, they’ve been in place for so long, and they could be considered additions to the Common Property, a compromise is in order.
That compromise could be a Motion on the Agenda for your next General Meeting (or for an Extraordinary Meeting if timing is an issue) that proposes a one-off sharing of costs between the O/C and those Proprietors who wish to replace the sunshades at the front of their Units / Lots, and a further provision that declares those items to be “Lot Owners’ Fixtures” once replaced. The ratio of that shared cost arrangement could be whatever is seen as fair, but in the circumstances you describe 50:50 seems appropriate to me.
Whatever the ratio, that mechanism could resolve the current impasse, put a lid on the proverbial “can of worms”, and ensure the consistency of the replacement sunshades (e.g. colour/design) in terms of maintaining the appearance of the Common Property; a positive for the O/C.
The quid-pro-quo for those Proprietors involved would be that whilst they’d be responsible for the on-going maintenance / repairs / replacements of the sunshades, “Lot Owners Fixtures” are usually covered under Strata Building Insurance Policies where the “loss” arises from “defined events” (e.g. storm damage).
I hope this helps!