"Script heavy mod" is a term that's thrown around a lot by the modding community and is regarded as causing problems for your game but what does it actually mean? Answers to what makes a mod "script heavy" vary from a mod having many script files to a single complex script with many calculations, or maybe a mod that runs constantly in the background. But scripted mods like the above cause no actual problem at all, as long as the scripts themselves are properly written; but, one single badly written script is enough to cause serious issues and ruin it all.
Script latency (also known as script lag) is another thing: simply put, script latency is how long it takes for scripts to finish running. The more scripts are active at a single moment in time, the more time it'll take for each script to process. You've probably noticed this on a moderately modded setup in script-based keybinds being a second or two late, or a scripted encounter being a bit slower than usual. It's harmless and unavoidable, even in vanilla there's a certain amount of script lag.
Here's what causes actual problems: badly coded scripts. Scripts that use easily spammable events without any safeguard, scripts that use Utility.Wait() function too recklessly, scripts that don't clean up on detach (leading to orphaned scripts) or don't unregister events when done, and more, are all sources of potential problems. These problems can vary from extremely high script latency (enough to interfere with FPS), to save bloat (abnormal save file growth leading to corruption), often paired with stack dumping (script calls get discarded because there's too many of them).
Read the mod description page, the bug reports page, the comments page, ask other modders. If you have some knowledge of Papyrus, it would be safest to open the script source files in said mod yourself and see if anything is off.
Previous Page | Next Page