For me the newest guide concept is to get to the runners with a single transition guide. Butt guide - transition guide - all runners to the tip.

Easier to do with light rods and lines, gets harder as line diameter goes up.

Marc,

Keep trying different set ups and experimenting!

Can you achieve your goals with a single transition guide? If so, try it, and do it!

A couple of very simple examples in your line of thinking from my own experience:

1) Vertical fishing crappie spinning rod: 6'3" MLXF blank; 4-10# Power Pro braid; 2500 size reel; double 1/8 jig rig with a three-way swivel; and mono/fluoro leaders. I used a size 12, Y-frame reduction guide straight to size 4 micro running guides. Why?
I don't need to cast with this rod. I let out line at the side of the boat - straight down to catch 1.5 pound or less fish. My single reduction guide is good enough to get what I want = super light rod weight that does the job. (This rod
will also cast as far as I need it to if called upon to do so; but I didn't build it to cast 150 ft., either)

2) Spiral wrapped casting rod: I re-built an off-the-rack, 6'9" St. Croix Avid MLXF with ALL size 4 micro guides in a Simple Spiral wrap set-up. Calcutta 50 reel; 4-15# braid. Throws as far as I need. The ALL micros made the rig the lightest it can be. Works for what I want and need from this rig.

This is all to say there is more innovation and information out there for the world of custom rod-building than ever before. Learn the physic and concepts and make them your guide to what you want to do.