We currently have the tags protocol and beacon but the tag standards, sensors, kitchen-appliances and over-the-air-updates. That's inconsistent. All those are either general concepts which have clearly defined elements like protocols (HTTPS) and standards (802.11x) or are very much countable like the kitchen appliances and sensors.
I'd suggest to make tags like theses plural and make the singular tag a synonym.
As Aurora0001 has stated in chat, a good rule of thumb is this:
my rule is this: the tag should satisfy the sentence "this question is about _____"
"this question is about flash memory" is ok
"this question is about microcontroller" - nope
Since nobody can vote on synonyms yet and the pluralization/hyphenation filters block us from doing this as users, we'll need the help of the mods which is currently the SE team supporting us in private beta.
In the future we should make tags like these plural from the beginning. If we do so, the pluralization filter should prevent the singular tags from being created if I am not mistaken. I do believe it works for hyphenating tags as well.