I've been working on something that might be worth giving a try! [1]
It's built more for specifically for software architecture rather than general whiteboarding, but we just recently added custom icon uploads so you could add whatever icons you want if you're more interested in hardware. The 'logical component' operates in two modes, one which is just a group, and one where it acts like a sub-board that scales its contents to fit the box.
[1] https://contexts.online