Salt creep happens when the membrane isn't being used so it makes more sense to me to flush it before every use because TDS still creeps after a flush and no use for a few days.
I flush it before because I make RO drinking water and use the brine water for coffee, plants, laundry, etc. so I make sure its flushed before use.
Even flushing after use, waiting a few days & checking before using it again you get TDS creep so I always flush before use but the short flush after use seems inadequate to me.
My BRS 4 stage value plus takes a good long flush before my TDS drops to single digits. I find it is over 070 TDS every time I start it if I haven't used it in a few days up to a week.
Really it depends on how often you use it, or don't use it. People who have it plumbed into an ATO (where it runs multiple times a day) may only need to flush it once or twice a week/2 weeks (maybe longer).
It really doesn't take long, even flushing it for a minute or two is better than nothing, your DI resin & your membrane will last longer.
Maybe Russ or someone will chime in.