[ImperialCrown]

Try to determine if brake fluid has entered the booster. It would pool at the bottom and a dipstick of sorts could be used as a check.
Conventional bleeding should be OK after the cylinder is bench bled, just don't let the ABS HCU run dry.
No aluminum m/cyl rebuild kits, replace it.

 

[ImperialCrown]

If fluid has entered the booster, the best practice is to replace both the booster and cylinder.