Well, you could just cut out the combined push/pull day like MU. I wondered about this as the Killroy program runs 4 days but my guys only go 3 days.
So either you cut out one day or you rotate 4 different days on a 3d/week schedule which gets dizzying to remember.
The support hold is just a static since it shouldn't move.
You can adjust volume with the lever and support training. For basic statics like support and L-sit, it shouldn't bother your elbows unless you work your planches with hands turned out or the straddle-L with hands turned out.
However, basic mastery of the ring support comes before back lever as far as your elbows are concerned. Same with a supinated german hang.