They tend to rust up just a little bit. Kind of a restrictive device for a performance vehicle.
There isn't anything harmful with 23 degrees. If you can get the rpm to where it is supposed to be and it doesn't ping at WOT, that's probably where it should be.
The only issue I can think of with that much initial advance is that the engine may be difficult to turn over hot, like St.Louis hot.
Those balancers also have the tendency to migrate the outer rings with age as well.
Just things to consider before you give the "banana" back.
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