Humanity has achieved far more than PHH, & transhumanism is one of them, now Magecraft & Od based arts(Basically nen) are as common as PE & Sciences in schools & colleges, common used as an extension of the body & technology which has advanced as pure tech, pure magic & magitek, in case one of them ever fails.
People are all semi-spiritual lifeforms, only taking damage from magic energy same as Servants & are as physically enhanced as the lowest Servant by default. This makes the Lostbelts Servants much stronger though since the people powering their fame boost are themselves much stronger. In a Super Weight scale an average citizen is easily a 3, a High 2 at least. All can commune with Phantasmals & other such magical entities.
Compared to Olympus where everyone has nanotech, everyone here has biotech in the form of SLIME, which comes in several forms, Internal Infusion(ICHOR), Biosuit(Symbiote), Bioships & slimes(water elementals) ranging from cute & little to the leviathans that roam the oceans(Harvesting materials & providing security), all blessed by Nimue(Now a full blown water goddess).
Citizens:
Ability to Digest basically anything, increased lifespan, Regen, Stamina, Strength, Durability, Energy Storage | Allow Shapeshift(SexShift. Parasyte, Martian(YJ), Slime(Tensura)), Form Appendages, Optical Camouflage, SelfPropelling, ManaMentalLink(Like Servants & Masters Have, or Ninshu for Naruto), Biosuit & Bioship(Young Justice) Land(Solid), Water(Liquid), Sky(Gas) & Space(Void) Modes
SLIME(Cleaning, Medicine, Packaging, Analyzer, Replicator, Synthesizer, 3D Printing, Prosthetics, Implants, Transplants, Eros, Clothes, Homunculus, ENA, “Flexible, Growing, Organic Weapons” Bioship (Shapeshift SelfPropelling MentalLink Autonomous)
(Preserver, Fridge, Vacuum, SkinCare, Shower, Cleaners, Dyes(ColourS/Overlord), Scanner(Biometrics), Printer(2D, 3D & Tattoo), Medigel, ENA, Biosuit, Bioship, Familiars, Avatars(Remote, RolePlaying, Experience Different Species, Size, Shape, Sex, etc..), Cloning(Body Transfer to reproduced mimicry identical to original), AVATAR, GEMs (Pokémon, Spyrite | Animal or Phantasmal Mimic Replace Animals as Mounts & in Zoos))
Preservation(Fridge Thermos Hydrogel Aerogel) Cleaning Health(Surgery Skincare Medigel *plants) Replication(2D & 3D Printing, VeganMeat, Materials, Repair, Restoration) Symbiote/Kagune Computer(TouchScreen, S-mail, Fax, Phone, Text, Games) Clothing(ColourS SizeAdjusting NoSeams SelfRepair Shapeshift AdjustableTraits Breathability NoSweatOrStains ScentAdjustable)
(I give up on putting images, search any of these on Googgle & you will get the picture. Pun Intended. )
In order, Suu core form, Suu blob form, Blue Kirby, Chaos 0, Suu Child Form, Suu Adult Form, Chaos 2, Orca, Plasma Elemental or Primal plasma (MTG), Sea Serpent, Azulongmon, Water Leviathan, Perfect Chaos)
Due to the slimes ability to reproduce anything they scanned or dissolved, so long as they have the necessary raw materials, and their ability to communicate this information between each other, they serve as an alternative to many electronics such as scanners, printers(2D & 3D), etc…
This ability to 3D Print Organic materials as led to all animal based materials & foods & other such resources to all be reproduced via slime mimicry, based on the information gathered from the original source, allowing Humanity to go completely vegan & end animal exploitation without having to abdicate from these resources(Leather, Meat, Eggs, Dairy, Etc…)
Filled the oceans with huge slimes & water dragons to scan, catalog & archive species information as well as protect ships, map terrain & currents. An equivalent was done on land, with the Earth's biosphere now being backed up by Project:GENOME_ARK, in case of disaster or unnatural species extinction.
Just to make it shorter( not short) I researched Equivalents to some of the other tech I had in mind.
They are basically symbiotes(Marvel)+Martians(DC YJ Without the downsides) I realized after writing
Aquatic Adaptation(Water Breathing, Pressure Resistance, Temperature Extremes Resistances, Refraction Vision, Dark Vision, Sonar)= ENA from nagi no asukara
GEM=BackUp Brain, Aura Body, Shapeshift, Remote Control, extension of Rin's Jewel magic, basically Xenoblade2 Blades + Familiars + Steven Universe Gems + Spyrite From xillia
Albion has its own Chaldea Security Organization, Called Atlas with ATLAS being CHALDEAS, Atlas in Egypt has been absorbed & better regulated now that the Magus Mentality is no longer tolerated. Meaning Camelot has access to everything there & therefore everything Chaldea & Atlas have, except more advanced due to starting development earlier. Widespread PROMETHEUS reactors, Spiritron Computers(METIS), iBorder, Rayshift, etc...
Near the time of the Tree appearing the situation was made public & Fate/Grand Order published in forms of Media, to pay respect to Chaldea in stopping the Incineration of Humanity. . . & To Boost Mash's Fame, & as a compromise to allow Senpai to be summoned there in case they somehow died.
Leonardo was not actually killed but kidnapped at the start & is working here alongside her LB self.
Simulation Romani & Solomon, made due to Mash passing on his legend in the Lostbelt, rewriting him into their throne of heroes, so the Tree summoned him as Solomon(Caster), Romani(AlterEgo) & Goetia(Avenger) in the summons ATLAS made before the Tree appeared. LB Olga is also there, loved by Marisbury this time due to The Clock Tower Magus Mentality not existing.
This would make it extra hard & actually compelling since the Lostbelt wouldn't be complete trash thus not being Divisive on whether it is better or not than PHH, something they have avoided too much in my opinion.
Olympus(Part2) would be replaced with Olympus Vs Albion when The Edges Of The Lostbelts finally touch & a fleet of Ehangwens & Prydwens, as well as a hanging gardens type Camelot come in over the Horizon