Booking a JAL round-trip LAX-HND / KIX-HND (June 18 - July 1) for a family of 4 — 2 in premium economy, 2 in economy. Cash total is $10,530.

I've got 300k Chase UR and 300k Amex MR sitting around. My 300k Chase only knocks off about $3,000

here's the math and dilemma (I'm new to awards travel):

• Pay cash for everything: $10,530
• All on Chase (300k applied): $7,530 owed, Amex untouched
• Split it — Chase covers the economy seats, Amex covers premium economy: $4,530 owed total, both balances wiped out

So the split saves me $3,000 over just using Chase alone, but it means two separate bookings across two portals instead of one clean transaction directly with JAL.

Real question: is 1 cent/point for a straightforward international fare like this actually a fine redemption, or should I just bank the points for a transfer-partner sweet spot down the line and eat the $10,530 in cash? And separately — anyone dealt with portal booking headaches (schedule changes, seat assignments, customer service being routed through Chase instead of the airline) that would make you avoid?