Been fiddling with an idea. Let the bashing begin. If it survives, I'll gen the algs for example solves for further scrutiny.
Philosophy and motivation:
Algorithmic methods are doing fairly well compared to block building methods, and for good reason. TPS on the new hardware has shot up and it makes sense to make best use of it. A method with a bearable number of algorithms, yet highly algorithmically reliant and with good recognition has the potential to beat a good deal of methods. A means to achieve that is to have 3 algorithmic steps (compared to 2 for CFOP for example); while ensuring that those algorithms do indeed tackle a large set of cases (2LLL CFOP handles ~15k cases).
Orientation steps are almost always recognition friendly as long as they involve one (or two) top colour (like TSLE is decent for recog, OLL is pretty good, etc. but LEOR EO is hard) Permutation steps are good for recognition if a single glance at a cube, and registering 4-5 stickers at most can uniquely identify each case (like 2 sided PLL recognition system if good, ZBLL recognition on the other hand is hard, so is 4x4 PLL).
Cube symmetries can play a huge role in reducing number of algorithms while getting tons of cases solved (There are 72 PLL cases, but symmetry reduces it to 22 (21+1)). These symmetries can be exploited much better once we think about it.
Based on these primers and a bit of work, there seems to be one very promising end to a solve using 3 algorithms:
Suppose a 2x2x3 is solved on DL; FR and BR edges are solved; and the remaining 5 edges are oriented (i.e. white/yellow facing up/down say).
Alg-1: orients 6 corners. This will be a short <R,U> alg; and surprisingly, there are very few cases thanks to the freedom of U layer and the S slice symmetry. Also, R2 setups cut this down much further. There are 23 + (4 x 8) + (2 x 8) = 71 cases, though only 39 algorithms excluding mirrors. If we consider R2 setups, this number goes below 30.
Alg-2: Permutes 6 corners. These will be <R,U,D> algs (<R2,U,D> is enough, but algs may get lengthy); and again surprisingly, there are very few cases thanks to the same freedom and symmetry. There are 5 + (4 x 6) + 18 = 47 cases, though only 29 algorithms excluding mirrors. 2 sided recognition is possible here.
Alg-3: L5EP, <M,U> gen 16 short algs very simple to recognise during the previous alg.
This 3 alg system, which without any reduction has 71+47+16 = 134 algs (CFOP has 78 excluding F2L) can reduce the cube state from a possible 6! * 5! * 3^5 / 2 = 10M cases! This is 700 times more than 15k of CFOP, instead of an expected sqrt(15k)~120. Basically, this algorithm system is better per algorithm required compared to 2LLL, plus has comparable to better recognition; and looking at the movesets potentially better and shorter algs.
Now to the hard part:
How do we achieve " a 2x2x3 is solved on DL; FR and BR edges are solved; and the remaining 5 edges are oriented"?
Two premises about this.
Firstly, blockbuilding is probably the best thing that can be done with the inspection time in terms of reducing the number of cubestates. A roux block does this slightly better than a petrus block, which is better than a cross; all solving the same number of pieces (counting centres, since roux centres aren't fixed).
Second, there is a reason CFOP is as successful as it is, and that is the symmetry in F2L. We can choose to do whichever F2L pair we please, and we can do these in any order. This is very good for a step that is neither algorithmic, nor block building; because we can simply do whatever we see first. Finally, we can use only the last pair to influence LL.
This gives us a beautiful way to achieve the above mentioned cubestate. A roux block can be done in inspection, and then each of the 4 edges UF, UB, DF and DB can be placed between corresponding centres in any order convenient; while influencing EO. Follow this with a rotation and you have your required cubestate! The best part is, this central "belt" doesn't have to align with FB, because at the end of the solve, we can do an AUF with an ADF and will be done.
The EO condition in the belt can be relaxed in a more advanced version of the method, where one can learn all L5E algs (roughly 200 cases, ~60 algs excluding mirrors and setups).
Summing it all up:
Intermediate version:
Step 1: FB (~6 moves)
Step 2: EO-Belt (~16 moves) <r,R,U>
Step 3: 6COLL (~13 moves) <R,U>
Step 4: 6CPLL (~12 moves) <R,U,D>
Step 5: L5EP (~13 moves) <M,U>
Avg ~ 60 moves
Advanced version:
Step 1: FB (~6 moves)
Step 2: Belt (~9 moves) <r,R,U>
Step 3: 6COLL (~13 moves) <R,U>
Step 4: 6CPLL (~12 moves) <R,U,D>
Step 5: L5E (~15 moves) <M,U>
Avg ~ 55 moves
Promising a higher TPS than CFOP, this should be pretty good. Let me know.