domains not updating after cron run, only updating once viewed entity view for domain

The remote info is being cached on the dashboard site, for performance reasons. To force update that information, there is a dedicated drush command to update remote information: drush drd:info. That way, you can control how frequently you need updated info about remote domains by running that command by a system crontab in the required sequence.

There is Best prectice → documentation available, where you can find some suggestions.