I included a list of wildly descriptive options over 1NT using a 2-Under approach. But, non of them included a double as an option. I wonder how detailed one could get with a doubkle also included.
For example, consider one scheme:
2C = both majors or one major and a minor. Advancer preferences major (2D for spade preference). If Overcaller had both majors, we play in Advancer's preferred suit. If Overcaller has a major-minor and Advancer preferences his major, we play in that major. If Overcaller has major-minor but Advancer preferences the other major, Overcaller bids his major and Responder elects contract (possibly bidding 2NT for the minor). This handles all hands with five of a major and 4+ of another suit (including the other major)
2D = four spades and longer minor or just long spades. Advancer bids 2S if he would want to play spades opposite spades and a longer minor or 2D if he would prefer the minor in that situation. Overcaller acts accordingly.
2H = just hearts
2S = just spades, stronger
X = both minors or just diamonds or 4414/4441 or 4144. Advancer preferences minor. If Overcaller has both minors, he passes Advancer's preference. With just diamonds, he corrects 2C to 2D or passes 2D. With 4414/4441, Overcaller bids 2H. With 4144, 2S.
That's a lot of coverage. Can even more be shown?
What about the same 2C as majors or major-minor. X as both minors, just diamonds, or four of either major and a longer minor. 2D, then, could be 4-4 majors, 1-4 or 4-1 minors. 2M as natural.
If 2D is allowed as one major (either), then 2H could be 4414 or 4441 and 2S 4144.
These allow all but one Ripstra shape at the two-level.
How about double as canape major-MINOR, or one major? Advancer bids 2C if he would prefer the minor in the major-minor canape, pass-or-correct. With both majors, Advancer bids 2D (or to ask for the major); after 2D, Advancer can return to the minor. After either 2C or 2D, Doubler can instead bid 2M as natural, one-suited. 2C is crunched Capp, still. 2H still 4414/4441. 2D as 1444 or one or both minors; if Advancer bids 2H, 2S shows one or both minors. If Advancer bids 2S, 2NT shows both minors but 3min is one-suited. (2D might promise four diamonds, perhaps, and thereby become a natural "treatment," GCC legal -- bid 3C immediately with just clubs.) 2S, then, as 4144, and all 4441 hands are handled.
The possibilities seem almost endless. Granted, some of this is so tight that it hampers Advancer bidding his own stuff. So, maybe the insane detail is best for pass-out or opposite a passed partner. Or, maybe it is just a curiosity or a brainstorming start. But, wow can you stack if you want to.