I agree. Say the odds are 1 in 50 something may shift in the house or the basement floor where the studs rest wasn’t poured to be load bearing. The question becomes do you want to call the insurance company and when they say why did you cut the beam? Your best answer is a guy on the internet said it would be ok.I was looking on Bailey floor joists (lsf system) and they specifically mention their being an alternative to engineered wood. I'm sure you could look at the load tables and get something of similar strength and gain the space you want. While I would never argue against having someone take a look see, if the joist you are cutting is supported on both sides of the stairwell I highly doubt it's the keystone piece that will bring your house down. or tear out the stairs and make them steeper(jk)
That’s kind of the point here. In suggesting help here we have to try and access the persons abilities as DIYer along with a lot of other things based on a tiny bit of information we know about them. Electrical also falls into the same category quite a bit what is a simple job for some of us can be a deadly task for someone else.