Are you sure the issues you are talking about are related to Baldurdash and not Dudleyfix? I am 100% sure that area transition to Ulgoth's Beard was broken when applying Dudley patch (the entire package, not individual fixes), but haven't experienced this with Baldurdash.
I haven't used Dudley fix, so I cannot comment on that, but the couple of times I used Baldurdash, Ulgoth's Beard transition was broken.
I have just run a test, with GOG's BG1 - The Original Saga with Baldurdash fixpack on top of it. Ulgoth's Beard is accessible from the north edge on both sides of the river of Wyrm's Crossing map.
Opening the Baldurdash fixpack archive you can notice there is no AR0900 file which means it does not mess with the Wyrm's Crossing map, from which you travel to Ulgoth's Beard. You must have had some other mods or patch that broke this area.