Skilled Worker visa dependents travel while waiting for curtailment

I am currently staying in the UK on a Skilled Worker visa, with a spouse and children as dependants. We are all EU nationals. I am about to resign from my current job, and leave the UK within a few weeks after that. My family, however, would like to stay behind until July. My spouse is currently working in the UK, and her quitting her job in the middle of the year could have devastating consequences for some vulnerable people she is caring for. However her job does not permit her to get a work visa independently.

From what I have heard (see e.g. https://www.immigrationboards.com/viewt ... 4#p2155129 ), there is a decent chance that the curtailment letter will arrive late enough that my spouse will be able to keep legally working this long. However, we will also need (for hardly avoidable reasons) to travel in and out of the country. While I know that this is generally discouraged (e.g. https://www.immigrationboards.com/post1 ... l#p1355954 and https://www.immigrationboards.com/trave ... 43471.html ), I do not completely understand all the risks - especially when there are multiple people (i.e. a family) involved, who do not necessarily travel together.

1. The most worrying thing I have read is this post: https://www.immigrationboards.com/viewt ... 8#p2152148 . It suggests that, upon my leaving, my family could end up in an illegal situation without even knowing it. Does that really ever happen? I know that they usually do not bother sending curtailment letters to people that they know to be already outside the UK. But what if the principal holder has left, but the dependants are still in: could they then still curtail the visa without notifying the dependants?

2. I understand that, at the moment that one of us tries to re-enter the UK after my Certificate of Sponsorship is no longer valid, the border officer could curtail our visa on the spot, without even the usual 60-day grace period. But what happens to the rest of the family, then? Would they receive a curtailment letter? Would *they* get the 60-day grace period?

3. Some sources suggest that this might happen even if the traveller enters through the e-Gates. E.g. here: https://www.kingsleynapley.co.uk/insigh ... s-answered , I read:

"If they are eligible to enter the UK using the eGates, sponsored workers should be aware that where their sponsored employment has ended, they could be landing in the UK as a visitor rather than as a sponsored worker. They may not find this out until they try to change their sponsor or visa category and this is refused on the basis they are in the UK as a visitor."

Do I understand correctly that the ONLY way this could happen is if the visa is curtailed while the traveller is outside the country (so that the curtailment letter is not sent)? Does having at least one (adult) member of the family stay in the UK at all times mitigate the risk (because, presumably, at least THEY would then get the curtailment letter)? (The risk seems fairly minimal, anyway - if we spend only a few days away from the UK, it would take extraordinarily bad luck for the curtailment to happen at that precise moment.)

4. Is anyone aware of any recent cases where the curtailment letter has been sent exclusively by post, and not by email? Postal mail delivery is notoriously unreliable in our neighbourhood, so I really hope this won't happen to us.