Vim3L + Toneboard Low Volume + Channel Imbalance

I have a Vim3L with attached Toneboard running Coreelec. Toneboard is running a signal to powered Genelec 4010A monitors. Two issues I need help with:

  1. Maximum volume is not very loud even with maximum boost set in Coreelec. Any way to boost volume without getting a passive preamp or additional hardware? Would a passive preamp do the trick, though? For movies it is mostly adequate, but music playback seems to lack boost option and max volume can be entirely inadequate. Kodi has a parametric EQ plugin. Cannot find anything of the sort for Coreelec. Any suggestions?

  2. I have a bit of a channel imbalance. Right channel is a dB or two louder, it seems. My monitors have no volume knobs, and I cannot seem to find a software fix for this. Any ideas here?