We don't have any philosophical objection to adjusting the work rules to fit new types of flying as long as we're getting something back to address the concerns which prompted the rules in the first place.
The reason for the day/night transition rule was to prevent multiple transitions between the regular ILN-XYZ-ILN night sort and the regular SDS day sort trips which would reek havoc on a guys sleep patterns (as you guys have found out with all of those out-and-backs that you are doing). The one-time per block exemption was to accommodate the Sunday trips and allow the addition of a single day duty period either into ILN on Sunday morning to end a block or out from ILN on Sunday afternoon to begin a block.
Clipper mentioned another example, the 767 side letter. That letter allowed them to build some 767 lines that did not comply with the minimum blocks of days off and minimum blocks of days on. This was needed because the first 767s did nothing but west coast trips which could not be flown back to back due to the FAA 8 in 24 rule. The letter wasn't just a "concession" on the work rule, however, in return we got a concession from them which was that any such line would have to have four extra days off, 19 vs. 15. Those lines tend to be rather popular with those who live in Ohio because of the extra days off. I think that they're also quite popular for folks with vacation weeks as the greater number of days off can produce bigger blocks off for a week of vacation.
In past years the company had come to us with requests for deviations that were completely one sided. They'd want us to just delete a sentence or paragraph from the contract with nothing in return and they had no interest in negotiating, they just wanted us to agree. Those requests never got anywhere. In recent months the company's attitude seems to have changed. They are now coming to us with a problem and are working with us, listening to our problems, trying to find a solution which will solve the problems on both sides. This has proven to be much more effective.
Why the change? I don't know. Maybe too much glycol leaked into the local water supply over the winter? The same change in attitude has apparently reached contract negotiations as well. I just hope it continues.