Yep, that's one way we did it in the 80's and earlier. I started (bought a board) in late 83.
The problem with the tie on system you mention is that the rope length and knot had to be exactly right. Too long and you had a sloppy boom. Too short and you could crush the mast when pulling the boom down.
Clamp on booms were a blessing.
Formula 160; iSonic 111; HiFly Move 105; Tiga 263; '85 Mistral Superlight.
Maui Sails TR 11.0; 9.2; 8.4; 7.6; 6.6; Maui Sails Switch 6.0; 5.2; Maui Sails Global 4.5; 4.0.