I am planning a trip for my dad ORD-BKK. He may be routed either ORD-DFW-NRT-BKK or ORD-LAX-NRT-BKK (mostly because I want to sign him up for platinum challenge and I need to pump the mileage above 10000). I am wondering, if his outbound leg is in coach but upgraded with an evip, will he have lounge access to AC or JAL lounge in NRT, where his continuing flight will be on JAL coach?

I have done a few searches, but I didn't find any information on lounge access with evip, but continuing with partner coach.

Also, he is thinking about doing a long, overnight layover in LAX to visit a family member. Assuming that his ORD-LAX-NRT segments are evip upgraded to C, will he be able to hang out at the one world lounges after his arrival that night (but before his departure next morning LAX-NRT)?