Advice on self-directed IRAs and SAFEs

For our friends and family round, we've had two investors looking to fund us through their respective self-directed IRAs. Unfortunately, it has been difficult to submit details of our SAFE agreement to the custodians for approval. One even asked for us to get a valuation through a 3rd party agent, which seems counter to the point of using a SAFE agreement.

Has anyone had success in securing funding from an investor using a self-directed IRA for the funds? Any specific experience with Strata Trust? Any advice on other ways to handle?