Sending Presentation to multiple displays via Airplay

Before I spend money on Roku devices that support Airplay, I wanted to first ask:

Can Airplay simultaneously cast to multiple Airplay devices during a Keynote presentation? If not, is there a programatic solution like writing a system service to allow a multicast type thing to send the extended display out to multiple Airplay display devices?

I use my MacBook Air Silicon to do Keynote presentations in presenter mode through an extended display. My main display on the laptop can have multiple windows open that I use for reference and the Keynote presentation is on the extended display. Some of the facilities I go into are not properly wired with a splitter to send my presentations out to multiple displays for easy view by my attendees.

Sending Presentation to multiple displays via Airplay
 
 
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