If farming raid red borders Doing a challenge for the encounter that drops what you need gives double loot, squad up with like minded guardians and farm challenge encounters to get em faster. I do realize that previous season weapons that are outside of raids are harder to farm so agree Xur should sell harmonizers or a red border weapon of your choice every week on top of that. Not sure if exotic quest rotators are still a thing to farm these seasonal weapons and if they are that would be the way to get em. Personally have every red border done when it was made available to farm so it's hard for me to know where it can be farmed nowadays.