I'd like to see a challenge with the transmutation tablet limited to nonrenewable resources, and no condensers. Relays (and maybe collectors) would still be fine for the purposes of charging klein stars. You could use a thaumcraft duplicator (if they still exist in v3) to serve a similar role as the transmutation tablet/condenser for those annoyingly rare items or until your farm is set up. I like the idea of requiring farm-able items to be farmed, but the transmutation tablet offers an easier alternative (and FTB isn't supposed to be easy). Also, all extreme EMC generation loops (e.g. blaze rod maceration) require condensers.