This is an excellent question. I also use some pentameld i110 gear and parsing results are much better than with their i130 IW counterparts so this could make sense.

Im not sure if the system could be able to "detect" which kind of materia did you put on your gear tho.

For example, if you meld 20 VIT and 20 PIE on a bard piece of gear just to increase your ilvl it should not be treated the same way than 20 CRT / DET. This is an extreme case with irrelevant stats of course but... not sure if the ilevel calculation could factor the weight of all stats even if we only consider the relevant ones.