Ah no the max I would go with the vanilla custard is 5%. Inused to mix it at 3% and it was good, but I’ve started mixing it a bit stronger as I vape smaller clouds these days. I reckon 8 would be overdoing it. I would suggest starting at 3-5 with the VC.
With the strawberries I find if you’re making a creamy or custard recipe it’s best to steep that first then add the strawberry. I’d say 3% max though, and I usually mix the 2 strawberry flavours.
It’s better to start at a lower % and work up if it’s not strong enough, and the FA ones are pretty concentrated.
Edit: the strawberry ripe is TFA. I think I prefer it to the FA strawberry but they’re good in combination.