As for retooling, I have pre-2017 Browns and post-2017 Browns (with the new stem markings), and I think that there are differences.
The older Browns are on my Filco Majestouch 2, which is noted for allegedly picking the smoother or better Browns for those models. These would be pre-retooling (I think the keyboard is from 2016) and have the old stems and housings. [Not vintage, though, just the intermediate period when Cherry let its tooling go downhill, say 2007-2017 or so.]
The old Browns were absolutely terrible when I got them. My first mech, and it felt worse than a rubber-dome to me. It didn't take long to adjust to the lighter weight and middle-actuation of the switches, though. It took a long time for the switches to break-in, maybe a year, but they are smoother now, and enjoyable with thick DCS-profile.
The new Browns, I received on a Varmilo VA87M and then a Leopold FC900R. These seemed different from the older pre-2017 Browns on my MJ2. The new Browns are not quite as scratchy out-of-the-box, and maybe even seemed a little smoother. The tactile bump is a little more distinct, although more of a subconscious 'click.' Some say the 'retooled' Browns are more like Gaterons than before. I've noticed that, a year later, the Browns on the VA87M have changed less than those of my Majestouch. The new ones seem smoother out-of-the-box, but my older models may have smoothed out more.
Anyway, I can't tell you for sure whether there are any definite changes, besides markings on the stem and housing. Maybe the tooling is a little newer, maybe they changed things a bit. Nobody seems to care enough to check!