I know startup founders that have raised Chinese money and not regretted it, but it's important that it be "dumb money", i.e. they give you cash and go away while you write an occasional investor update and grow the business. Active Chinese investors (i.e. anything where you give up board seats, decision-making power, strategic partnerships, etc.) are bad news. You want to be in a position where if your investors ask you for something you can just ignore them.

What reasonable investor would put themselves in that position? They're just going to give their money away and not have any say in what happens?

This is the same position that every retail investor, every LP of a venture or hedge fund, every shareholder of a company where the founder controls a majority of voting stock, and every person with a pension or 401(k) puts themselves into. You could argue about whether that's a stupid thing to do, but it's the vast majority of shareholders within the world, so stupid or not, lots of people do take that bargain.

Any VC that asks non-independent third parties to review your code should be shunned.

Whose value proposition to whom?

I've personally done this for multiple companies that the enterprise I work for has purchased.

In all cases it was a 1-day review, while supervised by someone from the company being purchased.

It seems perfectly reasonable to get an idea of the state of what you are planning to purchase.