SQLab bicycle seat performance kit

I have a problem with my SQLab bike saddle in that I sweat profusely.To solve the problem, I created a performance kit for the saddle.This requires drilling a slotted hole measuring 85 mm long and 17.6 mm wide into the saddle.I used a countersink drill bit for this and then quickly filed down the plastic with a file.Even if the top of the saddle looks a little frayed, it doesn't matter. It will be covered by the overhang later. I used ASA for printing.