I've been testing this recipy for over 3 months now.
It was difficult to balance out the sucralose and flavor in my opinion.
First I made it 80VG/20PG but I found that 75/25 is the best ratio for the flavors to get enhanced.
I lowered the sucralose to 1% because Capella gives a weird taste over 1%.
Stevia is a better option in my opinion but I can't find a better solution at this moment, even 0,5% will do.
I've made over 700ml of this recipy and found that this was best for me.
I upped the strawberry because I felt it lacked and because the Kiwi and watermelon do give a bitter taste but you can leave the strawberry at 6% or 6.5%, see what fits you best.