NVDA doesn't have to adopt every popular feature of other screen-readers to compete. I don't have much opinion about whether this feature is implemented in NVDA directly or by an add on. It is a peripheral feature and not an actual screen-reader feature. It is a proper question whether NVDA development time and resources should be put into this project. And an add on wouldn't divert NVDA time and resources. However, when it comes to add ons, NVDA should do what Window-eyes used to do, not because Window-eyes does it, but because it serves users well, is logical and there is no reason of any substance not to do it.
Window-eyes used to accomplish a number of functions by having a number of what it pretentiously called apps, they were really scripts, but they were available to users as add ons and were shipped with Window-eyes and were set to run at the time of installation. Many users of whatever screen-reader they use will never learn enough to know anything about add ons. there are a number of add ons that should be incorporated into NVDA as addons that are downloaded and are running when NVDA is run.
If this were done, the major objection against making a feature an add on would be done away with. the objection is that a lot of people will never know about add ons and never use whatever is being discussed. If this objection were done away with by having many add ons be included in NVDA as running add ons at the time of download and installation or portable use, the whole question and argument about whether something should be an add on could be done away with.
----- Original Message -----
When it comes to the new screen shade function in Jaws 2018 and if NVDA
should also have the same function the main question is whether or not
NVDA is in competition with other screen readers in order to get more
users or is NVDA just a free screen reader for those who can't afford to
pay for a screen reader.