Just an update after further fiddling. Even though the fireplace remote only has one button for On/Off operation, it definitely does emit two different commands to the remote receiver. I have been able to successfully establish both On and Off commands from the bond, all be it a little tricky as pressing the actual fireplace remote alternates the RF command on repeated presses. I was also able to integrate the new Bond device with Alexa.
One note about the fire place remote, it has a built in settable thermostat which turns the fireplace off after it reaches the set temp. I don’t believe you could do this with the Bond, (perhaps if you added a temp sensor to the Bond itself you could), but it would be nice if you could shut the fireplace off after a set amount of time. Home automation perhaps (ie. Nest temp, issue IFTTT command)?
A temperature sensor built into the bond might be useful for air conditioning as well.