If Product A & B have the same customisations i.e both product allow you to choose your choice of chocolate, milk or dark, but Product A sells out of milk choc, would Product B page also indicate there no more stock for Milk choc?
Thank you for your help
If you mean variant options then No, seperate variants with different inventory stock do not share inventory.
If you have some sort of product customization app you need to consult that apps documentation, it’s settings, or try a test order.
Do you recommend any?
Any what? please write in specific terms, and clarify if what you meant either variant options or an app