Let's not kid ourselves - no one actually uses the "suggest tag synonyms" feature.
It's slow, obscure, and difficult to obtain the relevant privileges. I even took the liberty of writing up a Meta Stack Exchange post about this under the Magic Wand Time Question. So for now, I think it might be more effective to circumvent this inefficiency by having this big Meta question where tag synonyms can be proposed. Then, they can be either voted upon like normal or simply brought to the attention of the users who possess the power and experience to make these changes. I'm thinking that each suggestion would be submitted as an answer to this question post, where they can be evaluated individually. I'll see if I can round up some examples.
I'm not usually a fan of dodging around the existing Stack Exchange protocols. SE seems to run very smoothly on the whole. So if this is something you, the moderation staff, or the community at large thinks is a bad idea (or if there is a better way to handle this), I would love to hear it. I'm just suggesting an idea here, I'll let the community judge its merits.