It's been a while but I used to have Platinum status with 90% of my stays at the same property. On one occasion when I checked in at that property I was given, with my room key, and I believe inadvertantly, an A5 sized computer printout with my name and address details etc on it but with two data fields highlighted, presumably for the desk clerk. The first field said "MR status" and the second "Top 25?". The highlights were against 'Platinum' and 'Yes'. So of course I handed it back but asked what it meant, and was told I was on file as a top 25 guest for that property. I was upgraded to what I believe was their best room - the Presidential Suite equivalent - on a number of occasions.

Anyway, my point is that with a limited number of suites available Platinum status alone might not guarantee any kind of upgrade (other than to the Concierge level) but that this 'Top 25?' flag might be a fast-track to them. But with your Platinum status achieved over so many properties you might not be visible in that radar.

Or maybe not