I'm not understanding what it is about the Steam client that you say is causing your issues. I don't use Steam, so I am totally unfamiliar with this. Is it flashing light, or what exactly? Any other sources of information about this?
There have been multiple discussions about it in a lot of places, including the Steam forums. It's easy enough to Google "Steam client migraine epilepsy" and find a bunch of information about it. Here's where one of the Steam mods decided to bury the issue under the beta forum in spite of it being a problem with the current version of the client. It's got a lot of links to other discussions about the problem too:
https://steamcommunity.com/groups/SteamClientBeta/discussions/3/2962768084999962...
Dozens of people posted publicly there and I know of a good number who avoided public discussion of the issue and just took it up privately with Steam support. There have been several people I know of who have provided direct proof of multiple problems, some more easily tested for and pinned down than others. Valve's response so far has included admitting they're aware of the problem but promising not to fix it, gaslighting users having issues, and violating the privacy rights of people affected by the problem.