Leave it as it is. I believe what you describe would give a 2 or 4 step difference between channels, which is too coarse an adjustment.
Sometimes I think kernelbob understands our preamp controller better than I do. Seriously, he's provided insights into how it does work and might work that have been very helpful.
But I've clearly failed to properly describe a potential fix to glynnw's original valid complaint re the channel balance algorithm (glynn you are incorrect in your interpretation).
Current Channel Balance Scheme
a) each balance adjust step increases that channel's volume by roughly 0.8 dB relative to the other channel which remains fixed
b) there are 9 total steps of adjustment available so a maximum of ~7.2 dB shift
c) although the channel balance does indeed shift, the total volume goes up as well because one side goes up 7.2 dB (after 9 steps) and the other remains fixed with 0 dB change. Call it 3.6 dB average increase in volume.
Proposed Channel Balance Scheme
a) each balance adjust step will alternate as follows (let's assume we want to shift balance to the right channel):
i) each odd step (1,3,5 etc) will INCREASE right channel volume by roughly 0.8 dB relative to the left channel which remains fixed. Avg volume increases by 0.4 dB.
ii) each even step (2,4,6 etc) will DECREASE left channel volume by ~ 0.8 dB while the right channel remains fixed. Avg volume increase is now back to 0 dB.
b) there are 9 total steps of adjustment available (by design) so a maximum of ~7.2 dB shift
c) the volume remains almost constant alternating between +0.4 dB and 0 dB.
d) the only way to increase the granularity further is by increasing the overall number of attenuation steps from 70 to some higher number. let's say it was increased to 120 steps. given that the attenuation range remains fixed at 60 dB overall, each step size would then be 0.5 dB.
Just to be crystal clear here, in either scheme all the user knows and does is press the right (or left) button on the remote to shift the channel balance to the right (or left). The rest is done by the software under the hood.