I’m probably the last person to ask! I’m just learning about how to modify / write DTHs myself, using the learn-by-example method, and have mainly been focusing on helping out with improving community-created DTHs for ZigBee-based sensors sold by Xioami.
I skimmed through NXP’s ZigBee Light Link User Guide, and the ZLL profile uses a reduced set of ZigBee clusters (0x0000, 0x0003, 0x0004, 0x0005, 0x0006, 0x0008, 0x0300) and also has a special ZLL commissioning cluster (0x1000).
I did not read whether a ZLL device may also use other clusters. Battery level is attribute 0x0020 in cluster 0x0001, and I notice in the fingerprint line of your DTH, in cluster 0x0001 is listed, so perhaps ZLL devices can use clusters / attributes outside the set for the ZLL profile?
Touchlink is a Light Link only feature that allows direct pairing of a ZLL device to other ZLL devices without a coordinator (hub.) It makes use of the special ZLL commissioning cluster. I don’t think it’s of much use in a ST environment because presumably you’d be pairing other ZigBee devices with a ST hub, and just using this switch as a controller.
Regarding configureReporting, I started with ST’s ZigBee reference here. For an example ZigBee device DTH that includes battery level reporting, the SmartThingsPublic ZigBee Button DTH is probably a good place to start. You may have to play with the min/maxVolts values, and check if the raw reported value is actually the Voltage * 10.
I hope that helps!