Cannot disable audible Park notifications during active call

[livehappy42]

Hi, group.
I'm having another weird one..

T46S (currently on 66.86.0.15, but issue presents on v85 and v84 also)
Broadworks Broadsoft
Park method: xsi
BLF are on phone

I can use the following params/values, and it will indeed silence any audible notifications about a parked call **on an idle phone**
features.parked_call_monitor.blf.ring_type = Resource:Silent.wav
features.pickup.blf_audio_enable = 0

My issue is when a user who is monitoring Park via BLF is on an active call,
and there is a call parked. The phone will alert every 10 seconds, and I cannot seem to disable this. It's pretty annoying when the cu has multiple park orbits and a decent call volume. Any suggestions would be appreciated!