Ask HN: Converting investor into a priced round

I have an investor that agreed to write a ticket of 150k at a certain val - lets call it 6 mill.

Now i've got an investor that will lead a priced round at 30 mill.

The first investor is strategic and we really need him onboard

DO i add the investor to the priced round term sheet, and just give him shares (based on the lower val)?

OR sign a term sheet at 6 mill val, right before the 30 mill valuation priced round?

Or issue him a SAFE that will convert when we sign the term sheet with the 30m val lead ?