My Vendors can edit their Micro Store layout in : Design > Layouts > Vendor Store > Edit Layouts.
I added New layout page for vendors with name "Vendor store 2" because some of vendors need to extra Micro storefront. I used dispatch "Custom: companies.products"
I think, they can have second microstore now.
But I don't know how I can show this new page in browser!
Please see attachment and help me.