I'm wondering if, in 2025, it's still possible to create multiple Google Ads accounts (MCC) for budget boost?

I know that in the past, it was possible to create up to 50 accounts under a single MCC (My Client Center) account without any issues, and using promo codes worked quite well.

Here's what I'd like to do:

1. Create multiple accounts for different domains
2. Spend €350 on each account to receive an additional €350 in promotional credit

This would effectively double my marketing budget.

So, is this still possible?
What’s your best strategy for increasing your marketing budget?

That's a smart way to grab €350