Hi John, 

When you reset the antispam settings, the setting on the Filtering card for "Domains card override filter actions" is defaulted back to disabled. This would cause the Domain Settings > Spam Filtering options to use the system spam filtering policy instead. You can give them back their customization by simply re-enabling that setting. 

We have Domains can override... selected but they cannot change the weights. A domain should be able to (at a minimum):

Hi John, 

Thanks for the clarification. This functionality was changed in Build 6985 (Feb 15, 2019):

Please feel free to review our accompanying blog post, Understanding Spam Filtering in SmarterMail, which was posted shortly after this release. 

Can we add a feature request for this to come back? If not, why?

We might like 10 as our weight but a client may want 9 or 11 as theirs. Each domain should have control over this weighting. I am not asking for filters, etc. as I can understand those should stay at the server level. The weight should be domain controllable.