Here is a design to support multiple browser-type testing per node:

Set up each node to create instances of multiple browser types. For this scenario, you would need three VM nodes, as follows:

• Windows 10/Firefox x 5 instances, Chrome x 5 instances, Edge x 5 instances
• macOS/Firefox x 5 instances, Chrome x 5 instances, Safari x 5 instances
• Linux/Firefox x 5 instances, Chrome x 5 instances, Opera x 5 instances

With this design, you are running 15 instances of different browser types per VM. Of course the number of instances can vary, as it is mostly based on how much memory is allocated to the virtual machine. So for this setup, you would only need 4 VMs (1 hub, 3 nodes), and you would have 45 virtual platforms to run against.