Last minute bookings at that price on JL or CX/KA would not be in the lowest discount economy classes which earn 5 TPs. They would tend to be in non discounted economy classes so earning 10/20 TP each way.

In fact on checking EF the only one way fares in economy filed by CX/KA/JL are in Y/B/H. There are no one way fares in anything less than Y/B/H.

For return fares the cheapest I can see some with base fares as low as £393 on JL but that is in V class which earns 10 TPs each way - and of course this is typically not available for last minute bookings as they seem to have 31 day advanced purchase requirements. The CX/KA fares all seem to be in Y/B/H so earn 20 TPs.

Are there actually any fares on JL/CX/KA which are in N/Q (for JL) or K, L, M, N, Q, S, V (for CX/KA) between HKG and TYO which cost £500-1000 and only earn 5 TPs each way for a last minute booking?