CShadowRun's UK Colemak layout inspired me to think about this, as he shifted all the keys on the bottom row one step to the left so that the Z is now on the VK_OEM_102 key that non-US keyboards have at the bottom left. Whatever used to be on that key gets re-inserted at the right hand end of the bottom row. (I think that somebody discussed this before, but I couldn't find the topic(s) right now.)
Moving the bottom row one step to the left seems to have advantages once you wrap your head around it! Those inward-downward stretches were always horrible. And the B becomes an easier stretch at the expense of the more rarely used K, which is all as it should be.
The biggest hassle may be having to type comma and stop with different fingers from before, as those are fairly common. The beauty of a bottom row left shift, otherwise, is precisely that you still type ZXCVBM (maybe even K if you want to) with the same fingers as before!
Ah... hang on... What if you only shifted HALF the row, keeping the right-hand side (which works well enough) as it is and putting the OEM_102 key ('#' on your board) in that awkward position in the middle?! Apart from the slightly unaesthetic plan of punctuating the main letter block with a punctuation key, this seems to me a good idea.
Maybe that'd appease people like Korivak who want to switch B and J because the B is on an awkward stretch and they don't care about the hotkey functionality for B? It'd even let those who DO like their Ctrl-B or whatever it is keep on using it in (approximately) the same position as before (see https://forum.colemak.com/viewtopic.php?id=234 for instance). At any rate, like Korivak's twist it would be an optional thing I guess.
The letter block posted by sorenk at https://forum.colemak.com/viewtopic.php?id=189 (in a topic about a totally different layout):
z q/w/f/g¦j l\u\y\-
a/r/s/t d:h n\e\i\o ,
/x/c/v p b:k m\,\.\?
I see that Sorenk has tried to make a shift of both the upper and lower rows that works even with US keyboards, but I'm not too convinced about that one - for one, the key staggering is just a little to the left at the upper row (on most boards) so that a shift there would be more dramatical; and secondly, I don't think the upwards stretches are so bad and they certainly don't compel me to angle my left hand the wrong way as it is (I want to be able to hit the G and number 6 keys!). It may not be a bad idea per se - I just think it sounds like overkill moving both the Z and the P around like that. Certainly not a great idea seen from that hotkey perspective.
It's too bad the US keyboards don't have the VK_OEM_102 key, or this could've been made a general rule. I'm tempted to do the same thing with my own keyboard! I wonder what Shai feels about the bottom half-row shift; that is, what he WOULD be feeling if all US keyboards DID have that extra key. (Gee, I wish my own keyboard had a Kana key - imagine the fun I could've had with THAT beauty!)
CShadowRun, let us know how you feel about that shift now that you've been using it some.