Anyhow, just sharing what I found. If you change the Culling Layer from 'Default' to Nothing, you deactivate the culling (auto-zoom) of the camera. I haven't got to check how lame in terms of performance this ends up being or the like, but it just works (besides de Inspector warning of "Please Assign Default..."). However, I must tell that this disables the culling entirely, e. g. the camera no longer avoids geometry that's on its way.
In my particular case however, that I'm working a SideScroller 2.5D it works like a charm
However, I opted for an even lazier and cool solution for the time being (I did rotated the camera view just a little tiny bit, enough to keep the player always visible so the culling don't get triggered.
If I get stuck with this solution I'll then keep delving into deeper hacks but for now I'll consider it solved.