Combine multiple points to polygons by property

I’m working on a website with a Cesium map, and I’m using turf.js for geo calculations.
I need to find a way to merge a large set of points on the map (with a fixed distance between them) to polygons, by a certain property.

For example, here is a set of points, with two different properties (marked red and orange):

And the desired output should be something like this:

The way I tried to approach this is by transforming each point into a square, and then use turf’s union on all squares that have the same property. This produced the second image above.
The problem with this solution is that I’m getting a large number of points (can be around 100K) and performing the union on them can sometimes take a very long time (up to 2 minutes), and I need to find a more performance efficient way of doing this.