I am aware of the workarounds, and have put one in place to fix this now. 

That's not the issue here.  The issue is that accidentally sending a list to the select object invisibly changes its behaviour and can produce some hard to find bugs in big patches. 
There are lots of other objects where this could happen, but [sel] is somewhat unique in that it won't output incorrect values to its main outlet but rather just stops sending bangs and sends to its second outlet.