Daryl-

Thanks for the note and perspective.
The ideal wad column for this (and my other) bore rifle is being developed as 'the right hunting load'.

My intent is to have a load that I can load and forget about until the right time in the field - that'll be as good and consistent then (hours/days/weeks later) as it is the moment I load it.
Two things I consider are water seal and stability of the internal components - including the stability of the state of the powder, to keep it dry from water and wad lube.
The 'dixie cup' over powder cup-wad card is there to keepin anything from the greased/lubed wads from seeping down into the powder. That's what drives my interest in running the 'dixie cup' cards over powder. I make them shallow, and load them with the cup side facing the powder. From there I drizzle a tiny bit of beeswax around the edge of the card to seal the powder from the lubed wad column. I've found that a beeswax/crisco greas cookie does a good job too.

My interest in running tight felt wads impregnated with the crisco/beeswax will help this issue as well.

The ring/circle/'donut' wad isn't so much there to center the ball as I'm running ball right at (for alloy) and just over (for pure, not hardened) groove size. That special donut wad is to further gas seal.
Here's the premise behind my using it: Diameter is less than half circumference. The felt wads are right at groove diameter. Under pressure they 'wrap' around the backside of the ball, essentially losing diameter in the process.
The donut wads take up the space between the ass end of the ball and the circumference of the ball, the wad underneath them pushing it forward - and the ball squeezing them open against the bore wall - creating a greater lubed gas seal.

See what I'm getting at there?
The effort to make the little donut wads is nothing, consider another three to six seconds per load.
I haven't even bothered to 'just run one flat wad' without a card over powder or donut under ball.
I'll try that to see how it goes and get back to you on this later.

--Tinker