I called up the garage to ask about a compression check and the tech convinced me to first get an accurate measure of the oil comsumption before paying money to dig around. As some of you posted, the flame trap replacement may solve the problem (fingers crossed!)

Since the flame trap replacement, no noticeable smoke on startup but I still am getting some kind of burning odour coming from either the exhaust or underneath the car. Not sure if it's oil burning or if it has something to do with a recent exhaust manifold and muffler replacement. We'll find out.

So it'll be a little while before I have the oil burn measure but I'll keep posting the progress.

Thanks for your replies - they're a huge help.