Lowering quality of collectibles as a FSH

I really wish we could manually lower the rarity or purity of caught fish. As a BTN or MIN you can control the rarity you get by your actions in raising it where as FSH gets his item rarity randomly distributed by the fish's size x10.

For somebody who is after Clusters in particular it's really troublesome to get on Water and Ice compared to the other elements. A lot of water-aspected collectible fish are mooches, so due to the 3 hour window of the Lv58 and Lv60 ones you're kind of forced to enroll Patience I or II and as such you'll in most cases where you get the collectible HQ it and get 8/8 rarity more often than not giving you Seaborne Aethersand instead.

Don't you think it would be nice if the "Lower Quality" option would allow us to just reduce its rarity instead of necessarily turn it into a regular normal item?