Somehow magically, I again get an option to define new “more modules” presets - so I’m able to do some adjustments again from the UI. Still wondering when exactly this does or doesn’t show up.
I just stumbled across the related discussion buried in the “darktable 3.0 for dummies” thread, which I hadn’t found earlier, where a post references the presets, a later post and MStraeten provided the reference how to redefine the module groups in darktable 3.0 for dummies (in 3 modules) - #70 by MStraeten. It may be a bit of a maintenance burden for upgrades to do so, but it looks easy enough to undo as well.
I still think adding and properly naming alternative presets and somehow hinting at disabling the base curve in the software itself rather than supplemental documentation would go a long way to make the filmicRGB-based flow more accessible.