I've been testing this out for a ranged build on my 5D(R). This seems to run a lot better. You can fend off lights when they come for you with the MPLas but your main weapon is the Gauss. I know it's not quirked which is really a shame on the chassis but I've been getting tired of the LBX10 being basically a spitball straw.
Ran this exact build while leveling up my 5D. It works well enough but really whats not to like about a GR with some back-up lasers on a surprisingly durable little 50 mech.