Custom labels per product or category? Singular/Plural?

Hi there! First of all, thanks for making this plugin. Unfortunately though setting the add to cart button labels per product type does not quite fit with our needs. As our shop is not selling goods but advertisements, I changed the label to “Add booking to cart” which suits for most products which are allowed to buy only once per order.

Some procucts however can be booked several times and the the customer can choose a number of bookings. I am having real problems to make it sound right for plural!
To make the button gramatically working, it should change to a plural text version (“Add bookings to cart”) as soon as the customer increases the quantity above 1.

The product type variants do not help because some of products which should have another label are simple products, others are variable.

I think it might be more helpful to set the labels per product category, however it could get complicated as one product can be in several categories.