I just went through the entire list and most don't even list what the mix ratios are or don't offer variations . Why is that so difficult for these people to do?
Some vendors state that the blends are proprietary, including the PG/VG mix while others post it but it may not be in an obvious place on the site. Some probably don't offer variations because of the effort involved in mixing every single bottle individually - which if you have a small shop, would be time intensive. It's a business decision, and it's their business so they get to decide what works best for them. Personally, I hate having to pick out too many options when selecting a juice - too many drop down menus for selections makes me overthink.
I'll let the vendor/creator decide what ratios work best for the flavour and if I agree - I'll buy more.
Oddly, Jugheads, who is a two person operation (done on the side of full time jubs) does offer the various mix options.