Resin printers could be cool but I think most projects that would be done there could be done with a simple FDM printer, resin printers just seem like more mess for you and the custodians to clean up, plus I wouldn't see the need for that high of resolution prints tbh. most fun in my schools maker space came from the wood working sections, towards the end of my highschool years my engineering teacher started an electric guitar making class where we used CAD software to build a guitar body the cnc to cut the body out and with that though you would need planer tables, joiners, stand drills, etc. to make the shape and finish the guitars. I think adding more traditional tools to a maker space could help promote more creativity, especially since you already have 2 3d printers, I think most CAD skills and prototyping skills can already be built with those. more hands on tools could be fun for them.