Multiple master links on the same chain
Nothing wrong with it other than aesthetics.

I have 3 master links on the 2.8 metre chain in my `bent.  Its glaringly obvious too cos the masters are shiny chrome and the rest of the chain is a dull cheap galv chain.

There might be a few grams difference in weight too, but realistically that's probably less than the weight of dirt on your bike.

Just use the same brand/style of master link, so you don't try and take one off the wrong way.