Settled Land - potential release

We are trustees of a strict settlement where the current tenant for life is keen to raise money by disentailing and then he selling assets. We/he has seen the STEP article by James Sheedy - albeit back in 2010.

Which appears to suggests that this course will give rise to no CGT or IHT liability. I feel that is fine for IHT - simply enlarging a life interest - but would have thought that taking aginst the trustee would give rise to a CGT liability - possibly subject to holdover?
Interested in any thoughts on the article or any other means of achieving the tenant for life’s wishes mitigating tax.