Quantity custom fields

Dear support,
I have a List with a quantity field. When the quantity gets to zero, the system hides it from list.
Since I would like to let it appear (but with the disabled="disabled" html attribute) could you advise me the file I should override?

Moreover, I read that quantity are removed after the booking, even with Offline payments and Pending status. This is very good for me, but I noticed that if I have a quantity field with 1 item left, and I make a group registration, the system still accepts that I assign that field to more than 1 member.
Do you think this can be solved in any way?

Thank you very much in advance
Lorenzo

Hello Lorenzo

Unfortunately, this is difficult to implement and there is not an easy way to customize it to have it works like that

So use it as how it's for now. When I am less busy, I will try to look at that feature again and find a way to improve it. Right now, code for that part is complicated and very difficult to customize

Tuan