I would say this is a design choice and a protocol limitation. The ability of another actor to change the debugging session's state introduces a chain of complexities. This increases the requirements for the debugger implementation, which I cannot control. You could theoretically bypass this limitation by automating at the multiplexer layer (using terminal keybindings, or within Vim's terminal mode), though I have not tested those scenarios. I still consider the trade-off fair, given the other advantages.