An alternative that people sometimes use is to create dummy extensions (with an exception rule) that forward to a shared parking, and then have the DECT phone transfer to the dummy extension.This way you can use the BLFs on Yealink T46U to monitor the Shared Parking like usual.
- DECT phone transfers a call to dummy extension ie. 200
- Dummy extension has this exception defined
- Caller ends up in SP1
- SP1 BLF on T46U changes color