Phew okay do I have a list for you lol. I went all out whilst listening to the football.
Firstly I noticed that HDE's confirmation of Dino Mech Gaiking isn't on the list yet.
So I tested all the Discotek releases I have that weren't already on the list and it's good news pretty much save a couple. Here we go
Working Not Working
8 Man After
Adieu Galaxy Express 999
Animal Treasure Island
Blue Submarine No.6 DVD (DTS Edition released in 2016)
Cardcaptor Sakura Movie 1 Blu Ray
Cutey Honey TV
Demon City Shinjuku
Devilman TV
Dr.Slump Movies 1-5
Galaxy Express 999 The Movie
Galaxy Express 999 Eternal Fantasy
Ghost Stories
Golden Boy
Golgo 13 The Professional DVD
Lily C.A.T.
Locke The Superman
Lupin the Third: Jigen's Gravestone Blu Ray (My UK BD player gave me no error code or a wrong region screen, it just loaded for abit then stopped)
Lupin the Third: Napoleon's Dictionary
Lupin the Third: The Castle of Cagliostro Blu Ray
Lupin the Third: The Fuma Conspiracy
Lupin the Third: The Mystery of Mamo
Ringing Bell
Saint Seiya Movies Vol.1
Saint Seiya Movies Vol.2
Sea Prince and the Fire Child
Space Adventure Cobra Movie DVD
Taro The Dragon Boy
Tekkaman Blade II DVD
Unico Double Feature Blu Ray
Violence Jack
Wicked City
Wonderful World Of Puss 'N' Boots
Golden Boy surprises me, the other 3 DVDs were the first three anime releases Discotek did. Lupin the 3rd Fuma conspiracy was 2007 and it seemed likely that everything after so far as DVD would work and that seems to be the case apart from the 2012 Golden Boy release. It's weird since Discotek had been releasing Anime pretty much exclusively from 2010 onwards.
I also found a few more CPM releases with 'ALL' on the back cover
A Wind Named Amnesia
Ayane's High kick
Black Jack Biohazard
Black Jack Incubation
Black Jack Infection
Black Jack Mutation
Black Jack Parasite
Black Jack Seizure
Black Jack Trauma
Dominion Tank Police
Garaga
Garzey's Wing
Grappler Baki The Ultimate Fighter
Legend of Lemnear
My My Mai
Project A-Ko
Project A-ko Love & Robots
Project A-Ko Uncivil Wars
They Were Eleven
Wild Cardz
Wrath of the Ninja The Yotoden Movie
Then curiosity set in and I tried the few CPM titles that said Region 1 on the back and well here's the results
Alien Nine
Angel Sanctuary
Birdy the Mighty Double Trouble
Birdy the Might Final Force
Darkside Blues
Harlock Saga
Silent Service
Strange Love
Tokyo Babylon
Urusei Yatsura Movie 2: Beautiful Dreamer
Virgin Fleet
I then had a sudden thought, perhaps alot of the Manga Entertainment titles would work also given they probably used the same disc across both US/UK regions. Here are the results
Angel Cop
Appleseed OVA
Astroboy 1980 Complete Collection
Black Magic M-66
Ghost Sweeper Mikami Movie
Guyver Bio Boosted Armor Vol.1
Guyver Bio Boosted Armor Vol.2
Highlander The Search for Vegeance
Macross II The Movie
Macross Plus Vol.1
Macross Plus Vol.2
Macross Plus Movie Edition
New Dominion Tank Police
Royal Space Force Wings of Honneamise
Psychic Wars
Shadow Skill
Street Fighter Alpha The Movie
Sword for Truth
The Dark Myth
Vampire Wars
Finally I tried a couple of release from relatively unknown publishers
Joe vs Joe Collection 1: The First 3 Rounds [AnimeWho]
Joe vs Joe Collection 2: The Final Rounds [AnimeWho]
Galaxy Express 999 TV Series Vol.1 [S'More Entertainment]
Bio Hunter [Urban Vision]
Golgo 13 Queen Bee [Urban Vision]
Vampire Hunter D [Urban Vision]
And with that me and my Samsung BD Player are going to take a well deserved break lol