I'm also running FTB Ultimate 1.0.1 on MCPC+ legacy (L31) with Dynmap 1.6 and the Forge Bridge. My first suggestion is to update MCPC+, as the older builds do not play well with Dynmap, Xycraft, Mystcraft, etc. at all.
Dynmap will lag a FTB ultimate server, no matter how conservatively it's...