How to use xpra like xvfb-run?

xvfb-run allows me to open a display and run a graphical app and when the app finishes xvfb closes too.

for example

xvfb-run --auto-servernum --server-args="-screen 0, 1920x1080x24" nw script.js 

is there a way to do this with xpra and xdummy?

current it requires to run 2 commands:

• xpra start :100 but only once
• DISPLAY=:100 vglrun nw script.js

basically I want to start the display, run my app, wait for it to close, close the display with a single command...