I'm surprised the 18MZ cannot help you out with the sequencing.
I posted some time ago with a sequencing question for the 12FG (a much less sophisticated radio)
& the answers I got solved the problem.
My problems were solved with slowing the retract SWITCH, not the servos, & the point mixing function.
Using a "Y" on the nose would reduce me to 3 channels but I need different end points so that is not possible.
The old fashioned way (mechanical servo arm & linkage adjustment) won't work?
Or spring load them closed & have the noseleg push them open?
I'm working on nosewheel doors for an MB339 at the moment, 4 doors, two cycle closed
when the wheel comes down, two remain open beside the leg. - John.