What fun! I'd only add that the new rear derailleur with its longer cage probably means the chain has to be lengthened. This may or may not have been done. You'd see the need most dramatically on the big chainwheel to big rear cog combination. That might put quite a strain on things if the chain is too short.

Of course that is not a good combo to use, but shifting into it unintentionally should be made a survivable event.