sharing you following findings : on checkmk version - 2.0.0p1
without Tag, i just enabled Network interface and switch port discovery rule by selecting Appearance of network interface = use Alias, on 1-2 switches i am getting port numbers and description of ports wherever it configured, but for other switch i am only getting description no any port numbers as provided snaps.
with 1 TAG : added two rule, one for alias and one for description but there is no any changes on result (tag choice - alias and desc)
with 1 Tag : added single rule to use alias and changed the condition of tag to desc - not working same result
activated pending changes same time while changing the rules and creating tags
seems with new checkmk version there is no any change on port discovery for few switches by applying tag, same time rule is working to identify idex or alias or desc. but result may very based on switch model
i used cisco 3850 and 9300 models where 3850 having correct port numbers by using rule selecting alias
for other models no changes