Following on from what Walter @krambriw said... One of our beta-testers has HSS running on a RPi-3B.
I'm running HSS on a RPi-4B with 2GB of RAM, Node-RED v2.0.5 with Buster OS.
I spent over 3-hours a month ago bringing one of my Pi(es) up-to-date as Node-RED v2 requires Buster.
I had to go from Jessie to Stretch and then Stretch to Buster (what a pain).
If I had to do that again, I'd just back-up the old Pi and flash a 'new' SD card with Buster.
I posted my experience on the forum.