I don't build rods, but I think having guides on both sides of the blank would put a lot of unnecessary strain on it
I think a better soloution would be to use oversized, low frame BNOG aluminum oxide casting guides as the first and second guides, then go with Hardaloys the rest of the way. I think Fuji makes the BNOGs up to 50 mm (I know they make a 40 mm). This would allow you to use a spinning reel with a long, shallow spool. And Lamiglas still makes some of their factory spinning rods with BNOG casting guides on them all the way up. Conoflex also makes what they call "dual rung" rods that can be used interchangeably between spinning and conventional, but I don't know what guides they use.
I also think placing guides on versus opposite the spline is overrated. As long as they're on or directly opposite, I don't think you'd have any worries about twisting under a load.