You ought to be able to just add '\n' to the end of your expression in an 'x//' + 'd' command sequence.
For example, "search the file for lines starting with [a-z] and delete the entire line" would be:

Edit ,x/^[a-z].+\n/d

On Fri, May 26, 2017 at 7:23 AM dexen deVries <dexen.devries@gmail.com> wrote:
given multi-line dot, spanning only part of a file, how do i construct
an Edit command to remove lines matching certain regular expression?

wanted to delete lines starting with one particular character; without
leaving an empty line behind, thus Edit s/X.+//d is not sufficient.