While we didn't try the meplex pads, we did try a couple of pads with adhesives...some intentionally some because we bought the wrong pads. In both cases, they were worse the plain straight pad. The adhesive pads either shifted (occasionally over the ulcer) or they stuck so tightly that they were hard on Emily's surrounding skin when they were removed. Again the aquafor adhered pads were effective most days and they were able to prevent stool from entering the ulcer if they diaper was changed quickly.
Emily is now almost 2 years past the ulceration. The site is largely scarred over. Only very small patches of red are still visible. The tissue is strong, but the resulting scar isn't pretty. She is lucky because it won't be visible with underwear on...so it shouldn't be too notable during gym class.
Hang in there! It does get better.