I didn't have much desire to switch to optical. In this application it doesn't seem to offer any advantages from what I have seen.
I have thought about the filament detector, but using a standard roller switch. But I thought that it had to be in the firmware. I run Octoprint as well, but I do not think it would be what supports that function. I do not know if the Creality/Afinibot motherboard supports filament detection. I believe my Titian does as it uses a different motherboard.
I have noticed the filament right up against the screw as well. I wanted to put a bowden tube up to it, but it is too close for that. I am thinking about either a spacer, or just relocating the motor to the top rail. I also am thinking about going dual extruder on mine...another reason to relocate both motors to the top. Likely with a bearing and swivel mechanism to reduce the bowden tube length and reduce forces on the extruder carriage.