Yeah, it's kinda weird. I can reproduce the behavior he talks about though.
It's ... different in Reaper because the "modes" (read, write, touch, etc) seems to be global to the track. I mean, it should be reading in either case but setting "Write" applies to the entire track unless you disable arming, which is kinda different from what I'm used to. In other cases every plugin (and the track itself, vol, pan, mute) can independently be in read, write, touch, etc, so it never comes up.
I mean, can you just go into ReaEQ below and put it in "Touch" or "Read" mode while ReaSurround is in "Write" at the same time or are those modes global to everything on the track?
Here's what I mean below where there are three plugins on a track. One plugin is in "Read", one is in "Touch", and the other plug is in "Write" and the track itself (Volume, Pan, Mute) isn't enabled for anything. But in Reaper that switching seems to always be global to the track, at the track level, so I may not be fully understanding it.
The modes above are "plugin specific", i.e. you can't have one parameter on a plugin in Touch while another parameter on that same plug is in Write, but the modes are independent for every device on the track, which is more of what I'm accustomed to.