I'm very willing to compromise on my wish list of deviations from ANSI, to help form a consensus of features that a majority of alternative users want.
My strongest preference is for a UNIX/HHKB layout on the main keyboard block, the most important (to me) feature of which is split backspace: I want the backspace function directly above Enter and the \` keys in the ANSI backspace position.
I like the Tsangan bottom row mostly for visual symmetry -- it's just prettier -- but it wouldn't hurt my typing experience too much to have a standard ANSI bottom row.
Split right shift is almost necessary on a 60%. I ordered my F77 with it for consistency with my smaller boards, and because, why not, I never hit the far right of the right shift key anyway. Contrariwise, there
is a reason not to do split right shift on a keyboard that has enough keys: it worsens the visual symmetry. So I could easily live without split right shift on a TKL or larger board.
The ISO left shift with ANSI enter is just something for fun to let me dabble with
Colemak Mod-DH ISO, but without going ISO on the right side of the board. I built myself a custom MX board with all of my suggested features. My initial experience suggests that I will not adopt the Colemak layout for serious daily work, so my beamspring does not have to be the keyboard where I have the weird ISO-ANSI hybrid.