I've used the https://mixitup.kunkalabs.com/ https://mixitup.kunkalabs.com/ library for similar functionality in the past. I am not sure how well it works with

I've used the https://mixitup.kunkalabs.com/ https://mixitup.kunkalabs.com/ library for similar functionality in the past. I am not sure how well it works with hundreds of thousands of items, but it does work well for the 600ish items that I am using it for.