Is cosrx aha/bha clarifying toner good for everyday use or every twice a week?

This product is very very gentle and can be used daily. Unless you notice side effects, it should be fine to continue as you do

This specific product is super gentle. If your skin can handle it, use it everyday. Scale back if your skin is getting dry, red, irritated, sensitized etc. Make sure you are wearing sunscreen though because exfoliating products make your skin photosensitive. As a general rule you should start by using exfoliating products once a week and work up to 3-4 times a week if your skin can handle it.

Start of with using it 2x a week and then make it more frequent so that you skin has time to build up resistance

I think since you have resilient skin, you don't need to worry. Its really gentle and the percentages of aha and bha in it are rrally low. I think the way you're using it is the best way. I have a friend who has really sensitive skin and she uses it at night daily, and hasn't complained at all.

I personally use this product every day and never have any problem since your skin is resilient I think it will be okay to use it everyday