Are you sure that the transmission was accurately filled and then checked on a level surface? Did you remove the level screw first and added oil until oil spills out of the level plug hole. If so, you probably did get the transmission full of oil. It sometimes takes a while for the oil to equalize from the clutch compartment side to the transmission side.
Are you sure that there is not an external leak out of any of the other seals that keep oil in the transmission, or gaskets or out of the vent line?
Crank seals do not usually get a hole in them. The sealing edges of the seal lips get flat and loose their sharp edges as they ware. Crank seals and minor air leaks get blamed for a lot of burned up and or seized pistons that were actually due to miss tuned carburetors and or riding styles that are not compatible with high performance two strokes.
Pressure testing the crankcase is not the end all answer to knowing if your crankcase is air tight. There are two lips on crank seals. One lip holds pressure and the other holds vacuum. A leaking vacuum lip on the seal is what causes lean conditions and not a leaking pressure lip on a crank seal. A leaking pressure lip just causes a very slight loss of power or sometimes blows transmission oil out of the transmission vent line.
The Vacuum lip is very flexible and delicate and is usually the first lip to ware out. The pressure lip on most OEM crank seals usually have a special coating that is brown or copper looking in appearance. Most of the online seal kits do not have good quality crank seals in them. Try to use OEM crank seals if possible. If you use OEM seals and load up the area between the two lips with light weight white grease or vaseline the crank seals will last forever
