Hey @Tim_Piumarta - love my Form1+ too 
… had some trials and tribulations, replaced a peel motor after only just 3 months (15 minute easy job), but the quality for the price of the printer is, as far as I’m concerned, unbeatable. Sure, there’s a learning curve, and you have to be willing to do some maintenance (just think of what people had to do to cars 100 years ago, then you’ll apprecite how little the maintenance of the Form1+ really is 
!), but the quality it spits out is great.
Anyway, to your problem: I suspect you have a faulty build platform. I have 4, and have used them all in several different resins; after EVERY build I clean down with IPA 99.9%, including the sides and into the crevice between the side and the top of the build platform. Never had any swelling or leaking. Since I’ve taken one apart (see this post - you don’t have to read everything, just scan through the pics), you can see what it looks like without touching yours - there is a seal, and, so long as this is intact, there should be no leakage; the plastic doesn’t seem to have any negative reaction to IPA… I’ve done about 250-300 prints in just over 3 months, and they’re all 4 fine - not TOTALLY clean, but definitely usable. The only thing I’ve done recently is to limit 2 to only clear, and the other 2 to all resins except clear after reading some advice from @BrentONeill
Any chance of you uploading a couple of high res pics?