NWBD tender offer

Natwest are offering 175p (plus accrued dividends) for NWBD.L: https://investegate.co.uk/nat.westminster-bk--natn-/rns/tender-offer/202106071556180760B/

This is a small premium to the pre-announcement market price, and higher than these have ever traded.  However, I'm minded not to accept, since:

• I don't need the cash - I have no good place to put it.
• I'm sitting on a large capital gain so would have a hefty tax bill.
• The running yield at 175p is about 5.1%.  This is not far off that of e.g. AV-A, which I also hold.  Trading one for the other just crystallises a tax bill which I could otherwise defer indefinitely (with its real cost diminishing each year due to inflation).
• I don't see any increased risk of Natwest attempting to redeem these by underhand means.  All shares repurchased will be cancelled, so couldn't be used to vote them out of existence.

I anticipate:

• This will be the only tender offer for some time.  Maybe there'll be another in 2026, around the time these stop qualifying as capital.  I'm not holding out for a better offer.
• Trading these will become even harder.  But that's fine, I have no plans to sell.  I'm happy to hold and reap the dividends indefinitely.
• There's obviously an ongoing risk that Natwest attempt to disappear these shares at par somehow.  This tender offer just makes it obvious they would rather these shares no longer existed.  I don't see the risk as that huge - even pre-tender-off these are only £140m-worth - surely not worth the legal/reputational impact of going down the Aviva route.