Is there no need to handle HAL_GetTick overflows

[wizhippo]

Is the startTime always less then the overflow?

If not these should be adjusted to account for the tick counter rollover

OpenFFBoard/Firmware/FFBoard/Src/EffectsCalculator.cpp

Line 121 in dc2d379

if(HAL_GetTick() < effect->startTime){

OpenFFBoard/Firmware/FFBoard/Src/EffectsCalculator.cpp

Line 125 in dc2d379

if (HAL_GetTick() > effect->startTime + effect->duration)

[Ultrawipf]

You are right overflows should be handled and i will change these sections.
But as it is so rare that an effect is started with delay at exactly the time the 32b 1ms tick overflows every 50 days its unlikely to have any impact.