In older handbooks, they often say that the parallel LC circuit used to
feed the end fed wire should replicate the output tank circuit of the
transmitter.

I have an end fed inverted "L" for 40 meters that works really well.
It's 32 feet vertical and 98 feet horizontal, with the far end 8 ft.
off the ground.

I use a parallel tuned circuit at the base in a weatherproof box and
it's fed with a 100 feet or so of RG 8 buried in PVC. The coax center
conductor is tapped up a turn or two from the bottom of the coil.

I consider this a single band antenna, and I use it only for 40 meters.

John