Here is my 2p worth, not on the edge of a bat, just my opinion....
The problem we have here that in general the shapes offered come as standard and those shapes will be based on...
1 bat model having a middle middle, another model will have a mid to low and another a low middle.
This the norm in the wider market... Because the bigger brands having to provide shops with a range of bats to suit all players and so there business model is just that...
Then we have those that buy in stock shapes and the range is similar to the above... They try to tweak a shape to suit a player and call it a custom but in general the offering is for you to go to a different model... eg. If you ask for a shape you like that has a high middle and ask them to lower it to suit you in general this cant be done...
Then you have those that can move a middle and balance it on any profile shape they make in the range. So you ask for a customization on a model you like the look of or shape of....
Then you have those that create whatever you want, based on discussions with the bat maker.... we dont have many of these left in the world. Some companies stop short of copying other peoples shapes but you know they could make it if they wanted to....
I'd bracket the last 2 as custom the levels of customization are different but then again so is the work involved...