When loading b2372, there's a big hang during one stage of base level load as function 36 takes around 10 seconds:

[ 9937] [b2372_GTAProce] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x140dd2b10 (2) took 195msec [ 10406] [b2372_GTAProce] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x1408f5b5c (53) took 461msec [ 11781] [b2372_GTAProce] MainThrd/ Loading content XML: dlc_patchDay23NGCRC:/content.xml [ 12390] [b2372_GTAProce] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x1407e3f7c (56) took 1981msec [ 12468] [b2372_GTAProce] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x14092011c (24) took 66msec [ 13265] [b2372_GTAProce] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x140921fcc (33) took 753msec [ 23093] [b2372_GTAProce] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x1408fe348 (36) took 9838msec [ 23156] [b2372_GTAProce] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x140e32d14 (38) took 58msec [ 24515] [b2372_GTAProce] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x1408fe2c4 (41) took 1346msec [ 24593] [b2372_GTAProce] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x140924768 (45) took 71msec

Equivalent on 1604 is usually a lot faster, to the extent that function 36 does not usually show in the logs at all as taking any time.

[ 9203] [ GTAProcess] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x140d92098 (2) took 250msec [ 9734] [ GTAProcess] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x1408cf618 (53) took 529msec [ 11015] [ GTAProcess] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x1407bfa90 (56) took 1272msec [ 11109] [ GTAProcess] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x1408f8dbc (24) took 67msec [ 11953] [ GTAProcess] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x1408fab38 (33) took 804msec [ 12000] [ GTAProcess] MainThrd/ LoadScreenFuncs::OnEnd: Instrumented function 0x140df1188 (38) took 51msec

It looks like function 36 is loading collisions that aren't cached, this may be related to the cache loader DLC fix being disabled here:

fivem/code/components/gta-streaming-five/src/CacheLoader.cpp

Lines 210 to 212 in f11661b

History shows this was originally disabled in 6ccc8cd, however the linked forum issues (https://forum.cfx.re/t/2494610 etc.) were rather related to d5a2c2d - MNBVH size - as it seems, leaving the cache disablement to be just 'there' serving no purpose other than making game load 10 seconds slower than it should be.

We could just re-enable this for 2189/2372 and run a quick pass through the game world to verify this makes sense.