Can I use Shimano's Di2 e-tube project software to do a custom lock out of additional small sprockets while in the small chainring?

Question

Context: I'm designing a drivetrain for a touring triple-tandem that I'd like to have a very wide gear ratio.

I plan to use the Shimano Di2 derailleurs (long cage RD-M9050-SGS and 3x11 FD-M9050) to limit cross chaining so that I can (hopefully) safely fit a wider cassette and a wider range triple crankset within the capacity of the long-cage rear derailleur.

I've read that Shimano's e-tube project software lets you pick from a limited set of supported chainring and cassette configurations. I'm looking at cranks (E.g. 44/33/22) and cassettes (e.g. the SRAM 10-42) that may not be in the Shimano dropdowns.

I know that some people on the internet suggest picking "similar" ones in the software and that you can customize the shift map when you use the right shifter in full-syncro mode.

What I don't know is:

1) Whether there are options like 44/33/22 in the crankset dropdown, and

2) If there's aren't super close options, can I manually enter my chainrings?

3) If necessary, can I ask the software to lock out EXTRA small sprockets on the cassette when in the smallest chainring?

To be specific, based on the quoted capacities (41-45 teeth) of the long-case derailleur, I've made the following chart of what I believe is safe:

My concern is that I understand that even if I enable full syncro-shift with a custom shift map that does protect unsafe gearing combinations, there will be a way to use the left shifter to get down into the lowest chainring while still in a low enough sprocket that the chain is too loose-- UNLESS I can ensure the derailleurs fully prevent those unsafe red-combinations.

More broadly, will I be able to set these components up in a way that Di2 prevents the unsafe cross-chaining in my desired drivetrain?

I tried playing with the software myself, but it wouldn't let me into the customize menus without having first bought all the Di2 components, which I have not yet.

Thanks so much.

Answer 1

My mountain bike doesn't have Di2, so this answer is based on my road bike Di2 experience..

1) Whether there are options like 44/33/22 in the crankset dropdown, and

The e-Tube project software will only list crankset options that are actually available in Di2 series hardware. What I mean by that is if you're using a road bike Di2 Front derailleur (Ultegra or Dura-Ace) but a 105-series cassette/chain ring, you won't be able to select that.

2) If there's aren't super close options, can I manually enter my chainrings?

Nope! Sorry :(

3) If necessary, can I ask the software to lock out EXTRA small sprockets on the cassette when in the smallest chainring?

Nope! But you could set up synchro-shift to determine when it automatically shifts to the next gear (and thus prevents cross-chaining for you). Note that the rider could always switch off synchro-shift (change to different shift mode) OR change from big to small chain ring when in the smallest sprocket and cause cross chaining that way.

More info on synchro-shift: https://di2center.com/2019/02/16/synchro-shift-how-does-it-work/ and https://di2center.com/2019/04/05/how-to-customise-synchronized-shift-settings/