Heyah! To adress both this question and the one previously asked in the comment section:

+ Yes, pocket portals can be accessed from anywhere, provided you have either the entrance portal (which will not break on deconstruction, so you can take it anywhere!), or subsequently a bookmark to the instance via either a flag or a placed teleporter.

- No, Pocket Portals are not a viable target for the Randomizing portals, and being very honest, probably never will. The intended purpose for Pocket Portals is to serve as a blank slate for the player to do as they wish; whether they want to use it for testing grounds for items, or as a warehouse, or even as a base of some sort.

If there's anything else you'd like me to answer, don't hesitate to ask!

The reason I asked whether randomizing portals got you do pocket portals is because they were listed under the same topic, and nothing was stated indicating that they were acessed through a craftable object.

No worries! The topic was extensively discussed and explained in the forums, so I saw that there was little to no reason to update the mod description. But yes indeed, Pocket Portals are craftable and do not break upon removal, nor wipe or destroy the world you access through them.

Random instances are found at first and cannot be harvested, but can be crafted afterwards with specific items obtained by exploring said random instances.