I'd have no problem with that. I think Fuaga is fine at LT, but I'm not sure he's ever going to be an elite pass protector which is what you really want at LT. It would also fill the hole we have at LG which could in turn improve the overall depth of the OL.
I think we are mostly fine on the OL now, other than the lack of depth, given the version of the Shanahan/Kubiak system that we use, but if a new OC comes in that wants to spread it out more or throw more, we may need a better LT.