Very interesting idea. I think it depends on precision with which that implant can communicate heading. If precision is 10 degrees or less, this can actually be extremely useful to visually impaired people.
I got the idea when I was learning to cross a wide street with a white cane. three lanes in each direction - and it proved to be a challenge because I would veer left or right and frequently get confused and lost. Then I thought a compass would be helpful, but a quick survey of compass apps on iOS showed that they are either visual, or show your heading as a number that can be read by VoiceOver, but it is still not very practical. So I thought that I need to encode heading as something that my brain can easily decipher during crossing the street. I have prior musical training, so that's why I decided to encode heading as a musical interval. This allows my app to communicate with about 10 degrees precision and in practice this is well enough to go on a straight line for long enough to cross the street.
Blind developer here; I often write tools for myself to perform some task that is not well supported by my screenreader. For example:
* I wrote an add-on that allows me to read HN comments in a structured way. A typical screenreader would present page in a linear manner, so you'd have to read all replies in order, which is quite tedious in popular posts. My add-on parses the page and identifies the level of each comment, and then I can navigate to previous/next comment at any level. So I can quickly check top-level comments and then read replies only if I'm interested.
* Another add-on makes Jupyter edit boxes to work with my screenreader. Jupyter was requiered at my company , so I either had to write that add-on or else. The way it works is that it sends Control+C Control+V keystrokes to the browser to retrieve contents and then presents them to me in an accessible window for editing. When I'm done it would Control+A Control+V new content back to edit box.
* BlindCompass - iOS app that I wrote for myself to navigate on the streets. One of the problems of blind people is that it is easy to lose the sense of heading, e.g. where is north vs South. So BlindCompass would read my heading and present it as a two-pitch sound, that allows me to deduce rough direction. It's also easy to figure out the right direction and just maintain it, so with BlindCompass I can cross large open spaces easily.