I would think if a $99 cad program can do this that Bentley implement this. Draftsight cad. www.draftsight2017.com/split-dimension.html
I believe this discussion has been mentioned a number of times to implement a capability to break or split dimension leaders.
https://communities.bentley.com/products/microstation/f/microstation-forum/21103/break-dimension-leader-lines/52281#52281
There appears to be a few Enhancement Requests raised to perform different types of break / split / jog operations when it comes to dimensions.
Enhancement 41208 - As a user I would like to be able to define a symbol that makes a dimension line appear jogged or broken and have it appear as part of the dimension element.
Enhancement 41215 - As a user I would like to be able to break a dimension element without dropping the dimension element.
Enhancement 86149 (old TR 302305) - When you add a dimension to an element and have the Extension line enabled and/or Terminators you are not able to break this extension/terminator in case the dimension text crosses with another text or dimension. User would like that this was a possibility, at the moment you have to drop the dimension and manual move around.
These enhancement will be evaluated by Bentley product management team for inclusion in future release of MicroStation
RegardsAndrew BellTechnical SupportBentley Systems