Alternate Dry Sump Design?

[Hobby Racer]

My 818R build uses an EZ36 flat 6 Subaru engine, so there are no off the self dry sump solutions to be had. My main concern is maintaining oil pressure while on track. As I am running the motor naturally aspirated, there is little benefit to creating a vacuum in the crankcase like there would be if running boost. Also the OEM pan is already only about 2 inches deep so there would be no height reduction by running a typical dry sump pan. This got me thinking, is it possible to run a dry sump system differently than the usual setup used in Subaru motors?

Typical Subaru setups run two or more scavenge stages and use the OEM pump instead of an external pressure stage. Oil moves through the system as follows:

1. Custom dry sump pan
2. External pump with multiple scavenge stages
3. Dry sump tank
4. OEM pump
5. External filter & cooler
6. Engine block

I was thinking of using the OEM pump as the scavenge system and then using an external pressure stage to feed the motor. The system would run in the following order:

1. OEM oil pan
2. OEM pump
3. External Filter & Cooler
4. Dry Sump Tank
5. External Pressure Stage
6. Engine block

This has some nice advantages. Fewer components, only a single pressure stage to drive off the crank, and less to modify on the engine. It uses the stock oil pan and fewer external lines. The oil is filtered and cooled before it enters the dry sump tank. I'm trying to think of any down sides to this idea, let me know what you think.