Quick answer: Unreal Niagara GPU emitter ignoring high spawn rate on console? Scalability quality settings clamp particle counts per platform - bypass with Force Solo or adjust EffectsQuality scaling.
Boss attack VFX spawns 20,000 particles on PC, ~4,000 on console. No code path between platforms differs.
Set Effect Type for the system
Niagara system > Effect Type > uncheck Scale Spawn Rate by Effects Quality on the relevant emitter. The default scales by the player's effects quality setting, which is lower on consoles.
Or override per-platform
On the emitter, expand Platform Set. Set Disable and Reduce per platform explicitly. Lets you cap effects on weak platforms without changing the artist-tuned high-end value.
Check EffectsQuality CVar
sg.EffectsQuality 4 in console. If this fixes the count, the platform's device profile sets it lower. Adjust in BaseDeviceProfiles.ini.
“Niagara respects scalability by default - which means a 'PC works' system isn't a 'console works' system without tuning.”
Tag every key VFX with its effect type at authoring time. Cleanup later is harder than the discipline up front.