I’ve seen a few wide kerf slotting blades, but they’re usually quite a small diameter (<4").
There is this (https://www.infinitytools.com/8-flat-top-blades) but it’s quite expensive, and has a 5/8" arbor, so won’t be suitable for “modern” machines with a 30mm arbor. For 1/4" wide cuts I’d still use a router table though!
