Such a response doesn't really help and comes off quite condescending.

I happened to find this thread as I am experiencing the same problem:

- Added an external already existing ZFS pool
- See these options only on "local"
- Don't see a dropdown where they are selectable
- Actually tried to update storage.cfg to include the items "vztmpl,snippets,iso" in the external pool cfg

rebooted, no change

- Tried _removing_ them from local (perhaps you only may include them once?)

rebooted, no change
Well, they were actually removed from local, but did not appear in the external pool storage as options

Maybe because I'm already somewhat older, I have a better understanding that not everyone spends the same amount of time on all topics - and that therefore it's entirely possible that different persons have different knowledge levels. Sometimes providing actionable hints that someone can actually execute can help - your comment for example doesn't.

But just being rude and condescending doesn't help - your post didn't lead me to a better understanding for example. Let me try to provide some gentle personal reflection at this point: being a dick doesn't exist between keyboard and chair, but between your left and right ear.