There are shallow spools for the 1500 and 2500 for sure. I have them. They are light - just under 6 grams! Just put one on the 1500 a few weeks ago. This change made it possible to cast 1/32 oz lures. I had already upgraded the line guide, pawl, worm gear and worm drive cog wheel with lighter items and bearings in the appropriate places. It's most certainly is a rabbit hole!

And there are light/shallow spools available for the Conquest too. ;-)