Nominees and Custodians, STEP 2 vs Trust Act 2000, etc., etc

Having responsibility for the appropriate management of a number of trusts, I would welcome thoughts from forum members on two aspects concerning nominees and custodians…

Firstly, where STEP 2 Standard and Special Provisions are written into the trust deed, are trustees allowed to nominate the trust settlor as a nominee and/or custodian? [NB Although the trust deed in the case I have in mind has a provision making the deed subject to English and Welsh, Scottish or Irish Law, depending on the jurisdiction in which the settlor lives, it appears that the requirements of, for example, Section 16 to 23 of the Trustee Act 2000 will not apply in this particular case, the determining provisions being those in the STEP 2 Standard and Special Provisions.]

Secondly, where there is a specific provision in the trust deed that Section 16, 17 and 22 of the Trustee Act 2000 shall not apply, together with a provision that trustees have the administrative powers to put or leave any shares, stocks, securities, insurance policies or other property (including money) in the names of nominee(s), does this confirm that trustees have the power to appoint the settlor as a nominee or custodian?

Added to these two specific points, if any forum members have experienced difficulties with nominee and/or custodian appointments, I would welcome their sharing those experiences with our community.

In anticipation of your help, thank you.