Hi Steve,
I have a  ASL node setup with
"First node" using the modified simpleusb drivers " I think you may have originally setup ASL_GPIO_Master" that was later forked (https://github.com/KG7QIN/ASL_GPIO) .
This allows the use of Pi GPIOs for the analog PTT and COS audio via a CM108 sound card -"4 wire E&M." - "I use a customised Pi Hat for this."
"Second node" is using USRP to Analog Bridge.
"First node" Using DTMF scripts in ASL for the *Tune.sh commands for the Mode change and the TG changes much similar to your original DVswitch approach with multiple .ini files.
At this stage all seems to be working well.
I did notice when activating a "mode" change command that the analog bridge service had to be restarted three times in the script when making the changes to the analog_bridge.ini  copying them to temp and then copying back to the opt/Analog_bridge directory or it would sometimes get stuck - This also happened to me on the original USRP controls using DVswitch (it also meant that with every "mode" change I had to register again but that didn't worry me.)
- What i am looking into now is a user dashboard to see what the Modes and Talkgroups are actually on visually and possibly  audio commands back over the "First Node"

(I think I am already in that group will take a look.) 
Thanks for all your great work.
Tim 
VK3TIM