I’d guess it will work on the back. I’ve used 8 sp brifters with a 7 sp freewheel and it works fine. Just center things on the middle cog and Shimano’s floating pulley will accommodate the minor differences at the top and bottom of the cluster. Just choose which end you want the empty click from the brifters.

As for the triple in front, no experience, but if you need a new f der they’re cheap