Questions on install of two smart lighting transformers

I have two existing lighting circuits that are run to the same point in my garage. I would use two smart lighting transformers to replace the existing transfomer. I have a couple of questions: My idea is to plug both into a single surge protector. 1) There is a note in the user manual about not using an extension cord. Does this count with a surge protector? 2) Is there any other issue with using a surge protector? There is also a note in the installation guide about not connecting two or more supplies in parallel. Electrically, this says to me that I should not use two transformers in parallel on the **same circuit**. Since they are on different circuits, they are not in parallel. And having them both plugged into the same outlet/surge protector has no bearing on the note about parallel installation. 3) Is the above a correct interpretation of the parallel power supplies note? Thanks!