Camera upgrade?

[Lopyt]

Though I generally enjoy thw camera on my cell phone, I am limited by the lens it comes with and dynamic range when shooting the sun. The resolution is fine for me. 

Would it be better for me to purchase one of those little lens clip on things for a 50mm, 75mm, and 240mm focal length, and some ND or mist filters, or should I get a phone with multiple lenses?

The current phone is the Samsung Galaxy S8, I was considering purchasing the Samsung Galaxy S10, or one of the Sony Xperia 5 models (if I can find one cheap). The S8 does everything perfectly well for me, except the camera. 

Is there a different smaller phone with an SD card slot and 3.5mm jack you would recommend for the camera? Needs to be able to record 4k 24fps.

Is there a big quality difference between the cheap lens kits and a more expensive one like Moment lenses? Would this be fixable in post processing?

Before you suggest it, I also have a Canon EOS 20D DSLR but its too large and heavy to carry with me constantly in the off chance I might want to take a photo.


I typically do landscape photography with no close subject.

[Benvisions]

Do whatever, no need to ask.