It's also possible to do this with a specialized vacuum advance can - although I have no idea where you'd get one nowadays. Or if you're running EFI, it will probably have this feature built in.
If you crack the VA can open and play with spring pressure you can make them work for boost retard, yes. Look up Tony Angelo’s YouTube channel, he just did a “how to” about it for his AWD cyclone. But that’s not reliable or a good solution.
