Solo 401k and personal funds - Arms length question

[Purnell C.]

I'm interested in lending both solo401K funds as well as personal funds to the same borrower. He's a flipper.  He wants to record one deed for his personal residence as opposed to recording a different deed each time he acquires a different property.  I've verified there is enough equity for my pennies.

If two deeds against his property are recorded, one in my name and one in the name of the solo401K, would this negate the arms length rule?