I've spent the last day and a half testing proposed solutions and trying to identify what specifically causes these spawning issues (when using texture mods). Unfortunately I've found no solution however have been able to confirm a few things which hopefully are helpful so someone else looking into this issue.
Both LML file streaming and file replacement can cause this issue.
Only using mods that solely use the file replacement method does not fix ped spawning issues. Using file streaming does not fix either. Using either the Replace/Stream load method does not seem to be the root cause and will not fix. Though I'm not saying how LML is actually loading these files is not to blame - it seems possible that how LML is operating could be causing this issue, or LML may be able to provide a fix/workaround.
Reasoning:
The following mods that only use File Replacement caused heavily reduced ped spawning. Using one or two at a time would result in seemingly normal ped spawning (same as when no mods are installed).
- WickedHorseMan UpscaledProps Windows
- WickedHorseMan UpscaledAnimals Birds
- WickedHorseMan UpscaledAnimals Reptiles
- WickedHorseMan UpscaledAnimals Mammals
The following mods that only use File Streaming caused heavily reduced ped spawning. Using one or two at a time would result in seemingly normal ped spawning (same as when no mods are installed).
- Instanity 4k Characters
- Nigeez TerrainTexturesOverhaul
- Energi HigherResolutionVegetation
More info on streaming vs replacing on the LML mod page description (at the end).
Repacking textures into File Replacement Directories (LML 'replace' folder) does not fix this issue.
Reasoning:
I took the time to repack each and every one of the above mods + a few others into the LML 'replace' folder under their correct file directories found in OpenIV. The mods all worked (mods loaded correctly), however this still caused heavily reduced ped spawning (same as before I repacked).
LML mods all either stream or replace files. The method used is specified in the mod's install.xml file. The stream and replace subfolders load via the same method as mods with their own subfolders (mods not installed into the stream or replace folder). It's just a different mod installation method... so basically the result should be no different - files are loaded into game via the same method. It makes no sense that repacking will make a difference.
This issue may be caused by a pool or video memory limit.
Reasoning:
When I was using any single mod on it's own, ped spawning would always appear to be normal. It was only when I used several that ped spawning would reduce.
For example:
Cazanu Improvements In Blood + Cazanu Upscaled Gore Textures + Instanity 4k Characters
Resulted in reduced ped spawning.
Cazanu Improvements In Blood + Instanity 4k Characters
Resulted in normal ped spawning.
Even adding AClassySliceOfToast Arthur's Gunslinger Jacket resulted in normal behaviour.
However, then adding WickedHorseMan UpscaledProps Windows caused reduced ped spawing (but it worked when used alone).
It seems that RDR2 has an extremely large amount of different memory and pool limits on several parts of the game (according to internal files such as gameconfig.xml).
Using different combinations of few mods at a time seemed to work reliably. So, it seems possible there is some kind of pool limit being hit when certain mods are used. It could also potentially could be a video memory limit (limited by game - not hardware).
This could be investigated further.
Note that changing gameconfig.xml limits (ped pools, memory limits) did not seem to change anything. I tried many different logical values on variables that sounded like they would have some impact however never found any change in game. (And yes, the gameconfig.xml file was installed correctly, though I couldn't completely verify it loaded). I set memory limits significantly higher than stock - up to the maximum my hardware would be able to physically support (20480MB VRAM hardware limit). All ped pools were almost doubled. No noticeable change of any kind. There is an excess of different gameconfig.xml files on Nexus that claim to help with memory and spawning issues, though I've seen no one actually confirm any have helped anything besides stuttering issues.
So I'm led to believe this is either an issue caused my how LML loads files in RDR2, or it is a pool limit or a memory limit (I think less probable).
I think there's at least a little to go on here. The memory and pool limits should be narrowed down further. I might spend more time on this later, however for now I'm going to just play with very few essential texture mods. Game looks great anyway 🙂
Additionally, if somehow the LML devs could be made aware of this issue then it's likely they may know of a potential cause/fix.
Also, If you're wondering how I was testing if the ped spawning issue was present:
I had one of my save files that would spawn a train outside Valentine upon load. This would either be immediately visible with passengers + wildlife, civilians walking/on horses or there would only be a few civilians riding horses + nothing else. I would reload the game a second time, every time, to verify.
tldr: LML loading method makes no difference whatsoever - ped spawning issue is likely an RDR2 pool or memory limit or an issue with LML.