Muting of RTT in conferencing?

6.2.1.2 Concurrent voice and RTT <Latest from #80 (closed)>

Where ICT provides bidirectional voice communication, and ICT provides RTT, the ICT shall allow concurrent voice and RTT.

NOTE 1: With multiparty communication, such as a conference system, conference floor control can be used to avoid confusion caused by multiple participants contributing at the same time.

Comment from Microsoft engineering team:

Not clear how this would work - audio and RTT are different streams and participants might not expect “mute” functionality (which includes device mute, platform mute and application mute) to be mirrored on RTT.

The 3GPP spec noted issues with rendering of RTT conferences (e.g. difficult for participants to track the conversation), so the concept of "RTT conference control" appears to be introduced as an attempt to make this seem more implementable. However, muting RTT input seems like it could surprise participants.