I tried with three different new worlds and they always ended up crashing within seconds.

https://gist.github.com/Aeron216/c2d32f18a3002bc93ab20d87b9c036e7

https://gist.github.com/Aeron216/bd21207222f7ca4d2881d624f14f9b99

https://gist.github.com/Aeron216/580949991224f3b95c4912b598e79e77

This was with loliasm-2.2

Stopped crashing after removing the mod.

Mod list:

https://gist.github.com/Aeron216/1712d3358cb0df08c81d97e631e31933

Not at my pc right now but FastFurnace is made obsolete with optimizeFurnaceRecipes. But I'll take a look at the crashes later on in the day. Thanks for reporting.

Also, it'd be nice if you can post latest.log and debug.log from the runs when you crashed.

Different new crash after adding it back in
https://gist.github.com/Aeron216/2272bb6e0e342b8c6a3e0b1469b0f99f
crash-2021-05-08_05.31.33-server.txt

latest
https://gist.github.com/Aeron216/8d20bf4fac8b034a841d14a724d1c70f
latest.log

debug
https://gist.github.com/Aeron216/0dd7f18b1e30aa175c8e4ae22a1e9201
debug.log is too large for uploading here (34 MB)

I guess there could be an overlap with optimizeFurnaceRecipes and FastWorkbench, maybe.

And maybe optimizeDataStructures is conflicting with Ruins Mod, Recurrent Complex
and RLTweaker (this one includes tweaks for Ruins and Recurrent Complex).

But no idea of why it conflicts with Potion Core and Apotheosis.