As far as your flavor issue, steeped or not, higher flavor percentage mutes flavor.
Your VG/PG mix isn't a factor. 70/30, 80/20 what ever VG/PG is a good general area to be. My 3% Double Chocolate (80/20 VG/PG 2% Double Chocolate, 1% Bavarian Cream and 3MG nic with .25% sucralose ) is fresh...