The better option is gradient reduction in processing. Details.
No filter will work well for LED lights and Andromeda. "Light pollution" filters don't magically filter out light pollution. They whack out hunks of the spectrum, hoping that what they whack is mostly light pollution, and what they pass contains most of the signal. That can work decently for emission nebulae, and metal vapor lights. By the time you get to LEDs and Andromeda, they arguably do more harm than good, costing you signal, and making color processing difficult.
What I use to combat light pollution is gradient reduction in processing. That actually identifies light pollution by its spatial variation, it's greatest at the horizon, least over head. Works on all targets, all sources of light pollution, equally well.
Suitable tools include ABE or DBE in PixInsight, WIPE in Startools, something in Astro Pixel Processor. There's a decent Gradient xTerminator plugin for Photoshop.
Pretty much all serious imagers use gradient reduction. Some add a light pollution filter, but mostly only with emission nebula.
Below is an Andromeda I did. Red Zone, Bortle 7, mag per arc sec squared low 18s. Nikon D5500. No (not so) magic light pollution filter was used, but I did work hard on gradient reduction.
37X120 = 1.2 hours, could have done better with more. Better version and all details here.
Edited by bobzeq25, 24 September 2020 - 10:59 PM.