We're out here using Nashville Numbers. Use of tablets and e-devices is catching on, opening possibilities Country and Bluegrass players (the majority of country folks out here) never needed to learn songs.
As far as charting goes, NNS rules the day as the means to write charts for sessions and archival.
I like that you include this method in your software. I don't know where the C & B charting musicians are but I have some to contribute when time allows. It's my speciality and look forward to posting in the near future.
Thanks, Keith Thomas.