Just to update incase anyone in the future may benefit from my research, I'm stuck between the Sony MDR-MV1's and the LCD-5's.
Everything is pushing me towards the Sony's; they are super comfortable and light, I can wear them for hours; have amazing bass for an open-back dynamic (there may be like 1 or 2 headphones that can rival it in this department); build quality is nice (amazing channel matching, no creaking, aluminium earcups); due to the design of the earpads, you can basically only wear these in one listening position, so it has very low positional variance which is also a huge plus when it comes to my usecase. It's a dynamic so I can see these lasting many, many years with proper care.
But...
I am worried about distortion. According to RTINGS, the Sony's weighted harmonic distortion is not too bad (attached lol), but I will be applying a subbass EQ (think Harman IE 2019 levels); also during a tone sweep, they are not the smoothest in the treble to my ear. There is a major dip in the treble which will also need to be boosted. I like to listen to a lot of Dolby Atmos content (using the Atmos renderer for headphones), which can have some insane swings in the dynamic range, especially in the bass.
These factors are the only thing that are making me consider the Audeze LCD-5. These are stupidly expensive (I will be buying used) but are pretty much the only planar I could find where I didn't have to compromise something major, every other planar I looked at either had QC issues, were extremely heavy or designed in a way that made them really annoying to wear (*cough* Moondrop planars). I will be compromising in pretty much every other department (comfort, lifespan of the headphone, positional consistency, price etc.), but if the Sony's will clip/distort then they are of no use.
Edit: I've decided to go with the Sony's, they offer too much for my use case to pass up.