(THIS ISSUE HAS NOW BEEN SOLVED)
Leaving this post incase anyone else has this issue.
Credit to Dave for helping.
I noticed when trying to map a custom hotkey to Zoom to selected (found in the right-click context menu when making a selection) that there is no option in preferences to allow you to do so.
Surely this one’s a really quick addition Sketchup team?
You can map Zoom extents, so it would be nice to quickly be able to cycle between Zoom selected and Extents with a simple keystroke.
If anyone else has a way of doing this please let me know.