Shimano trigger shifters are probably some of the most reliable pieces of kit in the world. I’ve got some 20+ year old XT shifters that still work excellently. Depending on a few things you might need to open them up and lube/grease (or spray gt85 and wet lube through the cable entry hole) them every 10 years or so but yeah, that’s an easy job and I’ve never seen a rapid fire fail.
Not sure if the spacing is the same between double and triple chainrings. If someone can confirm, you can use a triple shifter and set the derailleur limit screw so it can't pull to the third position.
Shimano trigger shifters are probably some of the most reliable pieces of kit in the world. I’ve got some 20+ year old XT shifters that still work excellently. Depending on a few things you might need to open them up and lube/grease (or spray gt85 and wet lube through the cable entry hole) them every 10 years or so but yeah, that’s an easy job and I’ve never seen a rapid fire fail.