Many options (if not all) in Plus! can be made very advanced. However, Plus! isn't only for the experts, but mostly for the "n00bs" (if I can use that disrespectful word). So many options will lack advanced features (eg: like reg. exp. for the filters)...
Many options can be made so advanced and tweakable that you need multiple screens for 1 option. Somewhere there is the need to draw a line. In Plus! this line is "mostly used", "n00b-friendlyness", that sort of stuff...