1x is just a lame fad. Get over it. How hard is it to get a 2x to shift properly?? You would lose at least 1/4 of the gear range.
Use the small front gear with the big 2/3rds of the back cogs. The opposite for the big front gear.
NEVER use the last 3 cogs crosschained either way. I never actually used a 2x, 3x sucked with constant double shifts. Only IGH for me now.