I had my car in to the dealership today having the front brake pads done and the rotors machined down to get rid of a little brake pulsation and I happened to end up having a chat with one of their body shop managers and a body technician. He kind of discouraged the 3M double sided tape solution I pitched to him actually... apparently there isn't enough clearance between the body and the trim to get the applique back clipped in with the tape down, as is the case with anything that's 0.5mm or more mm thick apparently. The thinnest of the double sided badge tape is 0.8mm. Doubted the 3M film idea I came up with as well actually, while that might be thin enough to get the trim back on and potentially strong enough to prevent paint eat-through by the bottom edge of the trim, that would probably just trap water inside the area behind the trim entering from the sides and create different kinds of rot altogether.
Back to the drawing board I guess. They are going to check with a couple of people who have more experience in this department and get back to me on Monday but one solution they floated is probably more inexpensive and potentially deals with the solution.
1) Order a brand new piece of chrome trim that hasn't had the drainage points drilled and cut into it as part of the numerous rust repairs and TSB so it has a continuous flush edge fitting to the body.
2) Coat the back of the new trim and the lower edge in the clear plasti-dip spray to dull and shield the sharp edges that vibrate into the paint
3) Replace existing trim on the vehicle with the new coated trim
4) Use automotive silicone sealant to seal the top, bottom, and sides of the trim, all the way around so that no water gets in and out of the area in the future