Well using ZachyCatGames' method, it looks like the overclock replaces the 1600Mhz clock, so I don't think I need to add the clock to sys-clk myself. I've attached some screens to show the current files I've built that show the regular clock working, the overclock working in place of 1600Mhz, and saltyNX/FPS counter working in Hyrule Warriors (One of the games that will actually run)
I've not played with voltages, all I did was follow ZachyCatGames' instruction which was to apply their patch to atmosphere, which gave me the modified stratosphere loader.kip, then uncomment
this line in minerva and rebuild hekate.
The pictures you see above are as far as I've gotten when it comes to booting my switch with the modified files, as you can see it's almost all working perfectly, except a large amount of games give me this error whenever I try to launch (which doesn't happen on stock).
My hekate boot.ini looks like
where the circled config is the overclock one that you see running in the first set of pictures, and the 'Atmosphere CFW' config is my stock emunand. But if I remove the kip1 line from the OC config, all games run just fine as you would expect, but obviously I don't get the overclock.
So I have no idea what could be causing a bunch of games to give me that error when the loader.kip builds without error, and all I've done is apply ZachyCatGames' pcv_ram_oc.diff file to it, which from what I can tell just adds the overclock in place of 1600Mhz and shouldn't make random games just stop booting and again I've not seen anyone else report this sort of problem in the thread, I just have no clue why it's happening.
Btw this was tested on different sd cards, with clean installs of atmos and hekate just to rule out any conflicts to existing stuff, same problem each time.