Block requests from Add-ons Manager

[Mc]

I would like to replace BlockSite by ABE and tried some USER rules. All work well, but one doesn't.
I'm often installing extensions locally, which are incompatible with my current version of SeaMonkey. So I don't need the version check from versioncheck.addons.mozilla.org, which is requested by the Add-ons Manager, when an extension gets installed. I tried blocking this with the rule:

Site versioncheck.addons.mozilla.org
Deny

I can block this request with BlockSite, but ABE does nothing here. What's wrong? Blocks ABE only browser sites and subsites, whereas BlockSite can block all kind of requests?

[therube]

Wouldn't extensions.checkCompatibility & extensions.checkUpdateSecurity work?

[Mc]

Wouldn't extensions.checkCompatibility & extensions.checkUpdateSecurity work?

One could think it would, but doesn't.
It's just an example where ABE seems to work different from BlockSite. There might be more.

[Giorgio Maone]

By design ABE takes care of not interfering with internal browser activity from privileged code. Not caring would be much simpler, since the checks are non-trivial, but would also break things in unexpected ways.

[Mc]

Blocking this I could do with a firewall, though, but you are certainly right. With ABE much more can be made wrong, than with BlockSite or a firewall.