With matomo-org/matomo#11524 it will be good to actually provide methods for setting and removing custom dimensions instead of having to use setCustomTrackingParameter(). We would need to see whether we reset them after the next request and whether we also allow passing custom dimensions with doTrackPageview, doTrackEvent etc similar to the JS tracker. We need to make sure to have consistent behaviour with JS tracker and if possible with current custom variables behaviour (if it makes sense)