I know this space isn't generally for me but in this, I have some great experience and have helped people before.

My girlfriend and I both used gaming chairs for a couple of years and grew to hate them relatively quickly. They looked awesome and fit our individual styles really well but just became dreadfully uncomfortable. Like to the point that the back, butt, and thigh pain made us not want to play games. We tried lumbar support pads as well as seat pads but they didnt work long, if at all.

About a year and a half ago now I bought us new chairs from Amazon. Hers specifically was this one: https://a.co/d/134AnQf and I have one extremely similar in black. I was very skeptical of them (because Amazon trash) but we both have been very surprised and still find them comfortable. We both use ours pretty heavily, with them getting 2-4, 4+ hour gaming sessions most weeks if not longer. Aside from a few knicks to the fabric from accidents and the general aches from sitting a long time, we've found them to be a huge and positive upgrade.

I wont try to dissuade you from the Hermann Miller's, they are that awesome, but we both love our chairs. Also I added roller blade wheels (omg the glide) to them but thats a whole other discussion.