hi Ken.
>So...(once again): which would be best? Stacked, identical and coaxial primaries or co-planar, identical and non-coaxial ones?
you can find the answer to this question by yourself, in usual way -
just by simulating, as you did before with currents and voltages, but
this time with mutual inductances and resulting coupling coefficients
instead.
probably INCA or some other of Antonio's programs can do the job,
can't tell for sure now, as i myself abandoned coiling completely
about 8 years ago and slowly returning to the hobby just right now : )
btw - am working on GLTC concept last days - its a "Greg Leyh TC", LOL.
jk - "gap-less tc" actually, tryin to use parallel tank circuit to
eliminate switch from conducting resonating current completely - not
much luck so far, but i'll keep tryin : )
my switch based on a SCR instead of MOSFET (don't like em at all) and
probably i'll use not a bunch of primaries as you planning, but some
sort of autotransformer action - to reduce voltage on the switch, like
from 20KV to about 2KV. and SCRs can handle huge ass currents just
fine.
>I'm getting way too old for this...
haha - same s*** here : D