My experience with upgrading devices from Dude:
Just click on one router at a time and “upgrade”.
Upgrading group failed miserably. Dude just send firmware to all routers without any sequence or delay. First router who get firmware (closest to Dude) immediately starts reboot, so f*ck all others, who was slow!
My topology is rings with one or several uplinks to central site, where Dude runs. So no. One time was enough for such “automagical” feature.
by the way, i did upgrade from 7.15.[1,2] to 7.16.1 and few routers just lost ospf part of config, whole ospf instance, areas, templates.
Very strange. Many others survive upgrade.
P.S. First reboot starts automatically, but you need manually reboot each router second time for routerboard fw. upgrade. Or just leave it until next time.