i spent some time searching for a way to create an avatar loader and found a solution, and i've just been testing with one of my outfit ids, but some attachments (glasses) don't get centered to the right position.

applying the outfit id:

local humanoid = script.Parent
local desc = game.Players:GetHumanoidDescriptionFromOutfitId(4117284206)
humanoid:ApplyDescription(desc)

i've tried to use the AttachmentPos/Right/Up/Forward and haven't gotten anywhere.