Score editor, multi-note tremolos

Hi there, is it possible to write multi-note tremolos such as these:

I was able to cheat by writing two quarter notes for the first one, and two half notes for the second one, then changing the noteheads, and manually adding a 3-line beam, but is there a better way of achieving this? The Build Trill function creates a single note attached to a short beam, not sure if I’m doing it wrong. Thank you!