Well, word "particle" is definitely related to sound...
Read comments in this function:
https://github.com/DarkoniusXNG/barebones/blob/101de1dc977f8fd2f8e04a08d6d8e7945b2a7da0/game/dota_addons/barebones/scripts/vscripts/addon_game_mode.lua#L16
If you need that sound for ability/item you can precache them in that item/ability instead so they will be precached only when item/ability appear first time in game (or precache required) instead of always during loading screen
#how to create a phoenix supernova explosion sound
eternal sun
mint olive
it's a sound, not particle, use soundfile instead
timid jay