JVC Parry's recent intriguing DMsGuild adventure Call from the Deep includes a hex map of an area of the Sword Coast from Forgotten Realms.
As JVC Parry is a third-party author outside of WotC, this suggests that DMsGuild allows use or recreation of their maps.
As I understand the DMsGuild guidelines, textual content from books and adventures can be used but not images outside of those that DMsGuild has published specifically for that use.
What DMsGuild allowed path are authors using to publish Forgotten Realms(FR) maps? Do authors have to recreate them with their own cartographers? Or is there a bank of map images somewhere that DMsGuild has provided?
Note: As opposed to this question which asks about the copyright issues of using Forgotten Realms maps - this question is asking for DMsGuild approved sources of FR maps allowed to DMsGuid authors or approaches that previous authors have taken that DMsGuild allows or states that they allow.