I personally feel like this is a conflict of interest and somewhat, self-dealing.
I concur. The Trustee should not personally benefit from the placement of trust funds anywhere.
Also, from the FDIC Trust Examination Manual:
A fiduciary has a duty to avoid conflicts of interest and self-dealing. However, total avoidance is not always possible. Furthermore, while the terms conflicts of interest and self-dealing are somewhat self-descriptive, they should not automatically be equated with exploitation or abuse by the fiduciary. For example, the use of own-bank deposits as a trust investment is by definition a conflict of interest and self-dealing, since the bank is investing funds held as a fiduciary with itself. Yet this action, in itself, is not necessarily abusive or detrimental to the interests of account beneficiaries. Before such investments are determined to be abusive or detrimental, an analysis of the facts surrounding the investment must be made by the examiner.
If the trustee is being personally compensated by the bank for the placement of the funds - good luck in explaining this to an examiner.