no way will it "fall off, your thinking of 70's wiggs,if its bonded correctly it will stay in place, even if the bond behind the hairline is less than perfect
its more than enough to hold it in place, you’ll crack the hairline, in a few bonds, good think about lace it’s pretty forgiving,
it looks like skin,or flaky skin when it lifts slightly, to the untrained eye,
just follow the bonding tips, search bonding, glue,
make sure your scalp is as dry as a desert, make sure the lace is a clean as you can get it, doesn’t have to be 100%,no one gets there system 100% clean. Make sure the lace is dry as a desert, totally dry, I can’t emphasis dry.thats a golden word.
Leave the glue on for at least 10 mins,assisting with a hairdryer on warm,cool,to speed up drying.
Wash your hands prior to applying glue, (you don’t want oils from your fingers mixing with the glue. Affecting the bond.

***the hairline, if in doubt that you’re scalp at the hairline is oily even after using alcohol, don’t take a chance.
Put a drop of shampoo onto the scalp only , lather, rinse ,dry.
That usually gets rid of any oil, reapply more alcohol , you shouldn’t need to, but as I keep harping on, dry surfaces.
The correct drying time, and you should get a rock solid bond you’ll be proud of that could last 3-4 days./*

*bonding time is dependent on, individual body chemistry, oiliness of skinn,sweat release, time of year. Climate.
Glue,glue app;lication,glue storage.
And possibly weight,(if your overweight you’re gonna sweat more in the summer)