Not sure what you are really trying to ascertain?
Was the trust set up in lifetime or under a will?
Is this trust still classified as settlor interest?
For income tax purposes ("settlor interested" for CGT purposes now abolished) following the death of the settlor(s) the trust would no longer be "settlor interested".
Whether prior to their death an interest in possession subsisted (as raised by section44) would depend upon the precise trust wording; if the settlor(s) prior to their death did possess an interest in possession the trust would still have been settlor interested but the provisions in this regard would be displaced by the interest in possession provisions with broadly the same consequences).