Accumulator not updating between fixed timestep ticks

[DasEtwas]

Is there any particular reason why FixedTimestepInfo is only updated shortly before a FixedTimestepStage runs its system?
I'm working on interpolating my physics between rendered frames. I planned on using FixedTimestepInfo::accumulator as the interpolator in a render sync system, but to my disappointment this doesn't work.

Thanks for the great work!

[DasEtwas]

To avoid updating it every frame, maybe one could store the timestamp of the last tick instead of the accumulator.