Beams really can block output. I sang from the other end at Robin Hoods Bay where the Dolphin has one. Pub now Closed, not just covid, up For Sale.
My singing teacher, ex opera, was adamant that there is not 'head tones, chest tones, husky, nasal,etc.' only the chest matters as stated early here. Not just opera singers but other music turns on stage can project too, I praise Spare Hands for using no PA and would suggest that folk singers rarely use PA and that is one of the benefits of the scene. See thread title.
(Maybe just me prefers Live voices at folk clubs to stages and mics.) They might return one day.