There are about 700 uses of ambox in the mainspace at the English Wikivoyage, including:
- 323 are https://en.wikivoyage.org/wiki/Template:Translate
- 222 are https://en.wikivoyage.org/wiki/Template:Style
- 67 are https://en.wikivoyage.org/wiki/Template:Movetocity
- 35 are https://en.wikivoyage.org/wiki/Template:Movetodistrict
- 24 are https://en.wikivoyage.org/wiki/Template:Merge
- 15 are https://en.wikivoyage.org/wiki/Template:Regions_discussion
- 8 are https://en.wikivoyage.org/wiki/Template:Districts_discussion
- 4 are https://en.wikivoyage.org/wiki/Template:Crop
- 3 are https://en.wikivoyage.org/wiki/Template:Transcription
IMO approximately none of these matter to non-editing readers, unless perhaps you can read whatever language is listed in the "translate" template, and you didn't know that a Wikivoyage existed in that language.
A few, such as https://en.wikivoyage.org/wiki/Template:Copyvio are about serious editing problems, but there are typically few or none in the mainspace at any given point in time. Additionally, templates such as https://en.wikivoyage.org/wiki/Template:Side_box use the mbox classes and might be affected.
I'm not sure that this project will provide any tangible benefit to readers of the English Wikivoyage.