I understand your frustration, and it's indeed a limitation right now. The pathfinder in Wurst calculates the whole path before starting to move and fails if it can't complete the path. So, for now, you can't
.goto a location outside of your render distance.
I'm keenly aware that this system needs improvement. But at this moment, I'm buried in other refactorings and unmerged pull requests that need my attention more urgently.
Rest assured though, it's on my radar for future tweaks and enhancements. Thanks for your patience and understanding!