[CA] How can a lender increase a loan’s principal balance while keeping the original lien priority?

A borrower has requested to increase the principal balance of an existing business-purpose loan secured by real property, and the question is how that increase should properly be structured and documented under California law so that the additional funds remain secured in the same first-priority lien position as the original loan rather than being treated as a junior advance. Specifically, what is the best and most customary approach for a lender in this situation, whether through a loan modification, restated or amended promissory note, modification of the deed of trust, or another structure, and what licensing, disclosure, or compliance considerations (if any) should be addressed when increasing the loan amount on an existing bridge loan that was brokered by a licensed real estate broker, funded by a licensed lending entity, and documented as a business-purpose transaction?

It does not.

I have, but they're clearly trying to sell me their own docs. I don't want their docs, and it's clear they're willing to point out any "issue" they can detect because it doesn't look like their docs. So I came here. A referral sent me.

No.