Extension of the new approach for switching to HSMP

I understand that the new approach to switching jobs based on work permit allows switching without requiring FLR(IED) in advance only by having another work permit and not for HSMP Visa.

Logically, if you are a current work permit holder, then switching over by getting another job by the route of work permit or by having HSMP visa should be treated similarly. Then why home office has not allowed HSMP visa holders to switch without requiring FLR(IED). How should we register this fact on Home office officials/decision makers?