Metric modulations AKA relative tempos don't set tempo right
P2 - Medium
S4 - Minor
Came up in #277292: support percent values to set the tempo
Metric modulations AKA relative tempos like quarter note equals dotted quarter don't set playback tempo right, but always to 120 BPM, the default.
bee7755, Windows 7, self-built using MSCV