Is it a Dual Extruder V3 or V3.1? The 3.1 upgrade helps with the heat creep issues. Alternatively, see Dual V3 - A Review - Wait for V4? - Heat Creep Still A Problem - #8 by b-morgan. I think that fan duct is a better solution than the 3.1 upgrade.
If you are only using one extruder, I don’t think you should have any heat creep issues with PLA.