Yup. I agree - I've been given suggestions by Hubitat staff both in the community forum and by email from support@hubitat.com
I think the slowdown in my hub can be attributed, in part, to badly written rules. I turned on logging for each rule, ran it, and changed it until there were no errors while it ran. I also removed a bunch of rules and virtual devices that I wasn't using.
At ~48 hours now, my hub has not had any slow downs.
But there is one rule that is still throwing errors - I don't know why that is, and I am hoping you or someone else can tell me what I've done wrong so I can fix it.
Thanks!
