Yep. Built an 80/60/40/20 vertical on that principal: what coil do I need to add 2m up a 20m vertical to make it resonant on …
Presuming centre loaded is more effective than base loaded, which is what an ATU is effectively doing.
So I have a 20m 1/4 wave vertical on a sota pole with a coil 2m up: 1 coil, 3 taps and bypassed for 20m.
However, a better solution seems to be winding the coil on spaced former that lets you clip on to any turn in the coil so you can tune for the paricular operating conditions you find yourself in. Details on reflector(below)… yet to try it here.