Wow, I know 1200 is quite savage and also very wary when using 1500 too. Sounds like the level of finish thickness couldn't take much wet sanding?
I only bought the Micro Mesh Guitar Kit set that starts at 4000 and on the Swampy Tele alternated between it and if not cutting enough reverted back to 2000 (can be bought at Autobarn and maybe Supercheap too).
On the current MMB-4 build it has had a couple of 1200 wet sanding sessions done after every 2nd coat and just did a 1500 session earlier tonight. Still plenty of finish and no bare timber which surprised me as the last few coats were a 50;50 blend with turps? Maybe the poly is softer than Tru Oil? Agree it would have added too much green tinge on the beast. Makes you wonder if rattle can white knight clear acrylic would be any better?