When I type in a tag that is a synonym source, a box with the synonym target pops up. This is good because when I am somewhat paying attention and know about synonyms, I see what kind of change will be applied once I submit my question and can change my mind if needed, e.g., when I notice that the tag is not about what I thought it was.
If I type with ignoring the boxes that pop up or have no idea how synonymisation works, this can lead to confusion. In the above example, I might get the impression that HTML (in general) is a fine topic to ask here. Or I might end up with a mistagged question because html makes sense for my question, but design doesn’t.
Therefore I request that once I finished typing a synonym source into the tag field (e.g., when hitting Space after typing it), it gets automatically replaced with the synonym target.
This feature request arose from this comment on Meta Academia.