I have yet to see even one example of that, given how many opt-outs the UK was granted and how much the UK actively encouraged the expansion of the EU.
Heck, the mere existence of Article 50 as an option puts it ahead of the behaviour of the federal government of the USA in the American Civil War.
It’s not the fault of Brussels or Berlin that the single largest party in Westminster:
* Invoked article 50, a 2-year process, a few months after it’s own Permanent Representative to the EU wrote that it would take ten years
* Followed this with a surprise general election, which unnecessarily lost them seats
* Set a bunch of “red lines” which were incompatible with their own goals
* Made no attempt to win over any skeptics in their own party, or in their opposition, after losing seats
* Spent 18 months trying to negotiate a withdrawal agreement, where the “Irish backstop” was their own solution to the RoI/NI border, because of their own red lines and the red lines of their supply and confidence partner, the DUP, who they only needed the support of because of losing seats in an election they didn’t need to call
* Chosen as Foreign Secretary a man who later said “fuck business” because they didn’t like his plan
* Were then surprised by the Westminster MPs, who had fairly consistently been ignored and lied to by the UK government, voting down the agreement by the largest margin on record
* Was unable to agree with itself if it did or didn’t need to plan for no deal because the conversations typically went “they need us more than we need them” “no” “that’s just project fear”
* Only seriously considered “no deal” in December 2018, describing it as “unforeseeable” despite having been warned of it for about two years continuously; and as a result contracted a ferry company with no money and no ferries who copied their terms and conditions from a fast food delivery company, to run services between a mothballed UK port that needed dredging and an already-at-capacity EU port
* Just had 3 (plus 8 opposition, total 11) MPs resign, including one Tory from a Tory safe seat, whose goal is now the destruction of the Tory party
What the EU has done is, apparently, start planning to send food parcels to the UK. The Express newspaper apparently calls that plan “blackmail”. I don’t even understand how anyone can say that without breaking into laughter.
The Irish backstop was the EU's solution, not the UK's. The talking point you're probably thinking of is that the UK-wide backstop was the UK's doing, which is technically true because the EU wanted the backstop to apply only to Northern Ireland - the UK negotiators objected because this would make a huge mess of the Good Friday Agreement (not to mention pissing off the DUP). I can't say I blame you for getting this wrong, since the whole point of this talking point was to leave people with the false impression that the backstop was the UK's doing.
“None” was ruled out by making it a red line to leave the customs union and single market even though that was originally something quite of leave campaigners thought was a silly idea. And it was ruled in by the WA backstop if the UK couldn’t figure out how to leave the Single Market without violating the Good Friday Agreement.
NI/RoI seems to violate the Good Friday Agreement. People argue about if it really does, but ultimately what matters is if the situation no longer satisfies the parties involved, and Sinn Fein says it doesn’t.
Irish Sea enrages the DUP because they want to be identical to the UK mainland (except for abortion laws and gay marriage etc).
It’s a mess.
One “solution” I’ve seen leavers suggest is for RoI to re-join the UK. The is generally met with derision by RoI commentators.