Just downloaded the most recent beta. The variable playback speed is nice. It appears to only have five steps for fast and two steps for slow which is fine. Is there a way to get a status indicator for playback speed?
Actually, the playback speed range ranges from 1/8x to 32x although the 32x may not be achievable with all codecs and resolutions and is dependent on the CPU power of your system. If the system can't keep up with the increased speed, then first non-reference frames are dropped, and if that isn't fast enough, then only I-frames are displayed. For MPEG2 files, generally 2 of every 3 frames is a non-reference frame. There is no such consistency for H264 and HEVC with some files actually having almost all frames being reference frames.
In terms of steps, the current multiplies are 2.0 when you go faster, i.e. 1x, 2x, 4x, 8x, 16, 32x and 0.5 when you go slower: 1x, 0.5x, 0.25x, 0.125x. You can change these multipliers with the option parameter for the K and L keys on Tools>Options>Shortcuts. Or if you like make a new set of keys such as S & D using smaller or higher multipliers. It is recommended, but not a requirement, that the decrease speed multiplier be the inverse of the Increase speed multiplier so that you eventually get back to 1x. Regardless, pressing pause/play (or space) will reset the playback speed to 1x.
Your idea of showing the playback speed is a good one and one we had thought of but didn't have a chance to implement.