What is the maximum VA load for each of the cable outlets on the transformer?

You can load the Hub-50 with a maximum of 50 VA in total. The distribution over the two cables does not have to be proportional.

The Hub-100 can be loaded with a maximum of 100 VA in total. The distribution over the two cables does not have to be proportional.

The Smart Hub-150 can be loaded with a total maximum of 150 VA. The distribution over the three cables does not have to be proportional. Please note that you can connect a maximum of 100VA to 1 cable. You can then connect a further 50 VA to the other two cables.