Like what the title had mentioned. There are times when a mod author deleted their mods from within curseforge site. Pack authors have a few modpacks design using their mods. So, when they delete the mod from the site. It essentially making it difficult to find the mod that is the cause for modpack being rejected from Curseforge.
My solution to this problem is within the curseforge launcher to have a symbol or an indication that they're a mod within the modpack mods list that is not hosted within curseforge. Thus, pack authors can quickly address the issue, without having to guess or waste time to hopefully find the mod, then to waste CurseForge moderator (or anyone who oversees modpacks) time.
Thank you for reading, hopefully, you can understand the difficulty of this problem at hand.