Forming a Series LLC under a SD IRA or 401k?

[Mike Ry]

Considering setting up a (TX) Series LLC under my self-directed 401k trust. Has anyone done this? I set up a series LLC last year, to handle my rentals, where I am the sole member. I'm wondering if there are wrinkles specific to the IRA/401k context? Or is the procedure identical to setting up a regular series LLC, except that the 401k trust will be the sole member, instead of an individual person?