I assume that you tried the lower the pickups and raise the pole screws, trick?
Totally agree with this.Raising the screw poles on those pickups will do nothing for you in single coil mode. They tap to slug coil.
I've found those pickups don't really sparkle. The newer TCI version like on the MEV and Paul's are brighter in single coil mode, while the older version is more of a mid cut.