That is possible factor-fiction. HMRC agree a sum of tax to be paid before probate is granted. Rest assured that anyone who thinks that is all they'll claim, merely because the executor is now able to distribute the estate and run matters, may be in for a nasty shock. I have known estates where HMRC kept arguing for more tax for a year, sometimes years; some they got, some they didn't.
It follows that, rather than distribute all the residue, the executor might pay only an instalment of whatever sum he thinks, allowing for all potential claims in the worst possible case, it is safe to pay. That could be a convenient round sum. The rest would then be paid out once it was settled that HMRC had stopped their further demands, those being settled one way or another, and had certified that all tax had been paid and no more would be demanded.
But you should still ask for accounts.