You can make custom packages yourself and upload them, but there's no information on how to remediate that with the packages that Fleetsmith themselves already installed (that I saw).
Yeah, the problem is they deleted controls without warning, potentially opening up their customers to risks. Had they automatically migrated their third party packages to custom packages or gave more time it would have been OK.
That's a lot of pain for admins, especially in a SME environment where I'm not aware of any viable alternatives …