Is there a faster way to pregen a large world other than using nucleus' -a flag?

Im trying to pregen a large world. I made some calculations and in the end it should be around 300Gb big.
I’ve used this command: 'world border gen -a --save 5m world"

I own a I9 9900K and I would like to know if theres anything I can do to get minecraft to actually use more than one thread. Atm one thread is at 100% useage with all other 15 do nothing at all.

Im running on 1.12.2 using the tekxit3 modpack with spongeforge and nucleus.

Are there any other configs I can tackle to speed this up?

All world generation stuff has to occur on the main thread if I recall… which means getting big fancy multi core CPU’s aren’t exactly helpful unless you intend on running several instance of minecraft.

I could be mistaken on the second half, but I am sure all World Gen has to occur on the main thread.

In Minecraft java, all world manipulation (world gen, block manipulation, entity manipulation, etc) occurs on the main thread and hates being on another thread.

So, short answer - as Axle2005 said - no. Long answer is, you would need to reprogram the entire server to work with multiple threads in mind. There are projects out there that have done this, LanternPowered (SpongeAPI) and Glowstone (Bukkit API) both are these projects, however not one of them support forge mods.

alright, thank you guys.