Starting a Securities-Backed Line of Credit (SBLOC)

BP Community, needing someone much smarter than I am.

I have looked into (and previously posted about) opening a SBLOC. I am set on doing so, however I am currently have my investment account and retirement accounts with Charles Schwab - I have a long time financial adviser that is an independent agent through them that has done fairly well for me. The minimum amount they require is $191,000 in liquid assets, 143K of which would be pledged as collateral to secure 100K line of credit.

I currently do not have the minimum amount required for Charles Schwab; but I know several others that have a lower minimum requirement. My issue, however, is that each of these corporations/banks/etc. that I have found require that you transfer your investment account to them (something I am not yet ready to do - I have played around with merely switching to low cost index funds, but that is for another day).

My question is this: does anyone know of an organization that would provide a SBLOC without needing you to switch over your investment account to them?

Any advice is appreciated!

Kyle