Hi,
I can't recommend trying to "hack it".
Of course, you can run the regular Teams app on a windows system and this can be on any device.
But you will lose all the functionality that the Teams room app offers. This app is optimized for this use case and allows your users to easily join and attend meetings.
Your request comes normally up when firms are also attending WebEx and Zoom meetings and want to attend the meetings with these devices as well. One solution for this can be the NEC infinity board. Other solutions like the Logitech Tap can also be used for other meetings but you have to decide before provisioning which to use.
The pricing for the teams room devices is pretty interesting. You can have look here to get an idea.
-us/microsoft-teams/across-devices/devices/category?devicetype=20
-us/MicrosoftTeams/room-systems/index
-display-solutions.com/p/eeme/en/Launch.xhtml?id=InfinityBoard
-us/product/tap
As you said you can license a room system for audio conferencing. This is needed for ad-hoc meetings and meetings planned with this account. In general, you use your personal account to plan the meeting and invite the meeting room.
Audio Conferencing can be licensed through a suite (E5) or an add-on (E3). More details can be found here:
-us/MicrosoftTeams/deploy-audio-conferencing-teams-landing-page