Currently, if Masque is loaded after an add-on that uses LCG but does NOT support Masque, it can cause issues with the glows not being skinned properly for add-ons that do support Masque. LCG has Masque set as an OptDep, but is usually embedded whic prevents it from being properly preloaded. Can you have LCG force-load Masque? Eg:

Line 13 from:

local Masque =  LibStub("Masque", true)

to

local Masque = C_AddOns.LoadAddOn("Masque") and LibStub("Masque", true)

That is unless you have a better solution. :P

Fixed in DeadlyBossMods/DeadlyBossMods#1340