Are the new Self-Directed Solo 401(k) documents I get for my investment account pre-approved by the IRS?

Yes. At Rocket Dollar, we sell IRS pre-approved retirement plans for your Self-Directed Solo 401(k)

A pre-approved retirement plan is a plan sold to employers by a document provider such as a financial institution or benefits practitioner. The document provider is the “pre-approved plan provider.” The document provider requests IRS approval (“pre-approval”) of a defined contribution or defined benefit plan document as meeting the requirements of Internal Revenue Code Sections 401, 403(a) or 403(b). The pre-approved plan provider then makes the IRS-approved plan available to adopting employers. The IRS also issues opinion letters for prototype IRAs.

* From the IRS website on pre-approved plans.

You can read more here.