Hello I am the creator and maintainer of gettext-volt. At the time that I created gettext-volt the umbrella xgettext-template project didn't support "contexts" and so I didn't add it. Admittedly, I don't exactly understand what they are used for but others have asked for them and apparently they must be useful or necessary.
So if anyone would like to help out we have been accumulating some donation funds over at https://opencollective.com/phalcon and at the moment we have thousands of dollars its going up at a consistent rate. I don't control those funds but I created the original Patreon effort and I can help to push for someone getting paid to improve this, if money is a motivating factor. Just submit the pay funding request and we can take it from there. Its not necessary to even run Phalcon or Volt but just to parse out the templates and there are already some tests there.