Yep, you have to rely upon tribal knowledge most of the time, and that can be dangerous depending on the sources. These companies should at a minimum, provide info on certain aspects such as (exactly) what you had asked in this thread. I just SMH vigorously when I receive a product - (especially for those marketed as DIY), that have no instructions not support.I agree. I can obviously figure it out on my own (or on the forum), but it would be a lot easier if they included instructions.
Someone really needs to shake up the industry and set some standards!