Here’s the step-by-step guide I used:
https://itch.io/blog/484532/how-to-update-nwjs-in-rpg-maker-mv-for-rpg-devs
It may be worth trying, since updating NW.js can improve the performance of the whole project, not only this plugin.
For reference, I tested the default NW.js 29.0 against NW.js 111.3 on a 100×100 map, and the performance difference was significant in my test project. I recommend making a backup before updating.
NW 29.0

NW 111.3