Would an extension be breaching the WA in a very specific and limited way?

I only ask because if I had decided to arrogantly and stupidly declare I didn't need an extension until the deadline for requesting was gone, what could I do?

I could manufacture some "unforeseen" issue with the original deal that would limit progress. Something I could blame the other party for...

Then of course it would just be common sense to extend.

I'm not saying that is what they are doing, but there has to be some reason they have done something which will obviously have a negative impact to the current negotiation, and I don't have much beyond sheer stupidity.