Considering the considerable effort that has gone into this by the time you are negotiating a contract, letting it fail over something that "is not important" and "is never enforced" would be very stupid of them.

So if they are unwilling to budge, that either means they were lying all along and the thing that's "never enforced" and is "not important" actually is very important to them and definitely will be enforced, or that they are a company that will enforce arbitrary and pointless rules on employees as long as they think they can.

Neither of which is a great advertisement for the company as an employer.