Why would you feel penalized if you couldn't run your home built engine in a crate class ? It is called a crate class for a reason. You assume that because someone would chose to run a crate class that they cant build a engine, how can you be sure that half the guys running a crate class couldn't build a better engine then you ? Maybe they have lives out side of racing and would rather buy a inexpensive engine and have some fun racing instead of being a full time mechanic after they come home from a full time job.
If like you stated you have to use a engine sealed by the same body that runs the races, well that makes no sense. Why couldn't a sealed factory engine be used ? If they unseal your engine, inspect then reseal it makes no sense unless the seals can be tampered with. If you cant just go out buy a used sealed engine and race then it seems like they are shooting themselves in the foot right off the bat.
Just wondering where you run your homebuilt engines ?