Honestly the recommended amount should be whatever terps come with the weed. If you're adding back terps you need better strains. There's a solventless extraction company in the states that claims they're getting around 15% terpenes without adding back.
Well that all sounds nice but in reality that's not what is happening. I don't think you understand the market. It's sorta of complicated.
In an ideal world yes the weed would be so full of terps thats pink unicorns would be emitted with the vape..........and my ass as well. But after it's turned into honey or another oil and vacuumed the taste is sucked out mostly. Shatter is even worse for no flavor. I've smoked dozens of different shatters and they all lack in terp imo anyway. Compared to a nice honey oil I find shatter lifeless or not so pleasant as some can be. Not saying shatter isn't nice but Diamonds or rosin is much better imo. Anyway doesn't matter what you and I want this is what many others want.
BIG FLAVOR.....same as other vaping is. Oh it not big is it? The kids are vaping these giant flavor profiles huge in those things.
Well weed smokers want that as well. Only they want it in the THC form instead. This is not the same a a yokan or puffco or other concentrate pens. I have some of those. These are throwaways and
not intended to be refill basically.
So in the disposable vape pen cart business they are several types of customers.
Customer by type.
1: The old school purist....only honey oil will do. Nothing added
2: Shatter cart customers. They like shatter anyway so yes in a pen as well.
3: Distillate Purist.....will only buy pure unflavored distillate...low in flavor or odor
4: Distillate strain flavor folks.....they want strains mimicked as close as possible NO flavor added. Just the terp profile.
5: Distillate Strain with flavors added. Mimick a strain and add bold flavors.
6: Distillate BOLD flavors folks. They want big bold fruit flavors in distillate nd don't care on it being strain related.
This is the range of carts available. The last two are the big sellers with honey third...a bird told me.
Young folks and ladies like the bold flavors the most....old kurmudgeons go for the honey.
But no one is immune.