For Blackcat20, at least with QFF SG, your upgrade chances or ops are higher than those of us who are QFF NB!
But yes, I have been at QFF SG before, so I know how nice it is to just flash the SG QFF card at the lounge entry point, to then just walk past with a smile.
I only fly rev $ to NZ nowadays, so with the subclass of J, I still have lounge access, but have to do it as part of the fare I paid.
When I fly QFd Y/subclass of it, as an NB on rev, and not enough points for an upgrade, I slum it down the back of the bus, hoping they have given me a shadow "seat mate", sometimes it works!
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As for Gojun, earning the points on the ground, (non flying) is good, but you really need to also fly, as others are doing, either for their job, or for "fun", because QF/QFF values those who fly a lot, ie, the ones with the higher status, and these can only be obtained from flying.
Years ago, we could obtain SC from credit card spends, but nowadays, they dont do this anymore.
If you can climb from NB to SG, your chances of J upgrades are a bit better than now, as an NB.
Yes, I know, its not cheap chasing status with QF.