Vulnerable Beneficiary trust created prior to 8 April 2013

Hi we have a discretionary trust that was created in 2011, The trusts only asset was a property and the settlors son (who would have met the criteria for a disabled person) occupied the property throughout until his recent death. There is no trust income and the trustees have now sold the property at a negligible gain so no income tax or CGT concerns. We are however considering whether the gift of the property was a CLT and whether the trust should have had a 10YA charge in 2021. There is nothing in the deed to stipulate that at least 50% of any payments from the trust would need to go to the disabled son. In this case there have been no payments from the trust during the disabled son’s lifetime but I assume that as the deed is silent on this point and is flexibly written to allow any beneficiary to benefit it can’t be a PET and will be a CLT with a potential 10YA charge?