Toot by Lanie CarmeloLanie Carmelo (caneandable.social)

There's nothing that's going to be accessible out-of-box, because the hard part of this isn't the custom post type or even the taxonomies associated with that, but the actual front-end filtering UI. What you could do, assuming the Jetpack portfolio feature lets you have project categories, is to enter your data, and then create a separate page called portfolio that doesn't loop through those posts, but acts as a landing page with links to your separate categories. This would also require a fair amount of manual work though since you're not looping through that custom post type and you need to keep track of its taxonomies.

Toot by James HJames H (allovertheplace.ca)

@Bruce @mcourcel @Pawpower A hot dog isn't a sandwich because sandwiches are made with two slices of bread, while a hot dog is (a) served in a bun which is technically one slice or (b) served on a plate without degrading the goodness of the hotdog. Serving sandwich middles on a plate without the bread can degrade their goodness, or, in the case of peanut butter and anything, be pretty much impossible. Oh God I've given this stuff way too much thought lol.

Toot by Carlos BlancoCarlos Blanco (melendez.land)

@Bruce As someone who loves everything the NVAccess Foundation continues to do, including NVDA, and yet is married to someone who did Jaws tech support escalations and some development for decades, my current contribution to the screen reader wars is: Use the right tool for the job, and a good toolbox will include multiple screen readers. And both NVDA and Jaws have points where one is better than the other. RIP my mentions I guess.