This is a good hint. The data is already provided by the Z-Way API but is nowhere displayed. I could add two channels to each device (thing): last update from device and last update from Z-Way. However, the properties of the channels would probably be the better solution, but in my opinion, these are nowhere displayed. What would you prefer: seperate channels or channel properties?
I think the conversation and the review of the pull request on Github are crucial. Perhaps there are some testers who write a short experience report in the conversation of the pull requests.
I think the easiest would be to follow (watch) my Github projects: forked openhab2-addons and ZWay-OpenHABConnector