CGT at end of trust

Mother died intestate in 2012 leaving 2 minor children (A & B) as the only statutory beneficiaries. Vulnerable beneficiary elections were submitted for both children. The main trust asset was the deceased’s house, which has been let for the duration of the trust and now has a gain of approx. £100k.

Child A reached 18 in April 2020 but, because of the decision in Crowe v Appleby, did not become absolutely entitled to a share of the property until child B reached 18 in December 2023.

A claim for hold-over relief is being considered but the loss of principal private residence relief is a factor as they may wish to live there in the future.

If hold-over relief is not claimed, presumably the vulnerable beneficiary treatment will apply only to child B’s share (as a bereaved minors trust) and child A’s will be charged at the trust rate (as an 18-25 trust)?

Is there any exemption from the requirement to submit a CGT on UK property report and pay the tax within 60 days in such circumstances? It seems very unfair to have such a short timescale to raise funds where there is a deemed disposal rather than an actual sale.