Using the WiiM app as a group device

[iconoclast]

Today I had a shower thought and started wondering why the WiiM app itself cannot join a multiroom group and act as an output. It's often that I play stuff throughout the house via either my WiiM Pro or Pro Plus with either my work or personal computers as source, but find myself wanting to do some chores (maybe while listening in to rather pointless work meetings) that are better enjoyed with noise cancelling buds via my phone (including in the garden). So then I stop playback on the source, and try to pick up things manually on the phone and restart everything.

But if I could just join the multiroom stream I already have going and enjoy that with noise cancelling headphones with the range advantages of Wi-Fi, that'd be pretty sweet.

I realize most people probably use the WiiM app as the main source, which I do not, so this will sound weird to them.

Does anyone do anything similar and have found a nice, low friction way of achieving this?