For reference, the lower fill line will submerge an empty platform by about 2mm and the max fill line will reach about 2/3 up the platform as you’re seeing. Some geometries may displace IPA at the maximum fill line but that’s at the upper limits of part bounding boxes.
Submerging the platform shouldn’t case issue and won’t leach byproducts into the IPA. Some older platforms had small openings that would allow IPA to enter them though we took steps to correct this a while back. If your platforms are older, it might be worth checking to ensure that IPA isn’t entering the platform.