Don’t have a definitive explicit source I can point to, just what I have picked up in forums about better mapping to fit the panels capabilities, I.e. it is not baked into the signal - which certainly makes logical sense.
The closest I can think of something more concrete - though a little tangential - was Stacey Spears on LG OLED where the TV was using its light sensor - before Dolby Vision IQ was announced - to adjust with the RPU in cinema home mode on those TV I think from the C9 or CX models - indicating they adjust at TV side.
I recall that was on the blu-ray forums.
There are also plenty of comparison videos out there from dmdreview reset_9999 etc. which show differences.
Ultimately there are numerous factors and I take the view you are the person looking take a critical eye and if it looks correct to you across a variety of content then that’s what matters, for me tv-led is quite a bit better in my setup.
side note: From what I understand LLDV was initially for gaming to get the most of the Dolby Vision experience without any lag - and because Sony had under powered SoC in their first DV TV’s it was “repurposed” for standard content as well.