This is dedicated to two perhaps minor wishes but I hear them echoed everywhere I go.
"Glue" - Permit two separate co-planar dimension strings to become one string. If separate dimension styles the first pick defines the "good" string, the style to use.
"Split" - The opposite, create two separate strings by selecting a point along the dimension string. The pick point defines which string the section selected remains attached to. In other words you split near the side you want the split segment to remain connected to. Maybe images would be clearer?
Or the reverse, but either way I'd take it!
Include the "Delete Inner Segment" option on the Options Bar! This way we just remove the selected segment and any between the first selection and a second, just like it works on walls/lines etc.