Given that "Space Age Edition" and not "2.0 Edition" is in the title, I thought that it would work with Space Age. But since the rockets are changed with the DLC, it doesn't seem to work. Well it's too heavy for the rockets now. Or am I misunderstanding something?

Same here, wondering too!

If I could finally find time to play, I would have realised that already ;-)
and whoever plays faster than me is welcome to submit reports.

the home page also says:

Launched for Factorio 2.0
compatibility test running...

and the thread says

[LAUNCHED....] Factorio 2.0 (Space Age) ...still testing

for reference, the rocket capacity is 1 ton or 1000kg. if that helps you figure it out sooner, glad to be of help.

Hey no worries, I was just wondering. Make sure to enjoy playing the game and DLC first :)

the ion cannon now has a weight of 1000kg
and if at least 1 of them in the hub inventory, build a radar to install them for the current planet

Perfect! Thank you so much! Works like a charm!