Considering a JL flight from TYO-ORD and then transiting from ORD-YYZ. If I have to pick up baggage in ORD so does that mean I have to exit security and can't use the terminal bus within security to go from T5 to T1?

Also wondering if anyone has experience getting JL at check-in to connect to an AA booking? Since Alaska doesn't mixed partner redemptions and an AA flight from ORD to YYZ would have different baggage allowances, wanted to see if the extra baggage fees could be avoided.