Network Reliability Engineering Community

Connecting more than 3 vqfx in the network

I would like to create some network configuration lesson with more than 3 vqfx devices. Is there posibility to achieve it?
I am aware of the following note in the docs

You can use up to three of these in a lesson, currently, due to the way that snapshotting affects MAC address changes at the QEMU level. (In short, it doesn’t work).

Does it apply to vqfx-speedy only, or vqfx-full has the same problem? May I have 3 vqfx-speedy and 3 vqfx-full in the same lesson?

Furthermore I want to connect utility image with vqfx (to emulate linux machine connected to switch).
I have copied lesson-12 (jsnapy) to another lesson directory successfully, changed its id, and configured connections in lesson.meta.yaml to look like this (last connection has been added):

- a: vqfx1
  b: vqfx2
- a: vqfx2
  b: vqfx3
- a: vqfx3
  b: vqfx1
- a: linux1
  b: vqfx1

However, I am not able to ping vqfx1 from linux1 terminal. What should I configure to connect linux1 to any vqfx?