History Question About U.S. Tasking

I only flew one contest with the ground panels and TP crews. Then radical new technology arrived in the form of Instamatic cameras!

Does anyone recall when:

Designated Launch became common? Soaring mag has several mentions of it going live in 1977 but was it optional at first?

When we stopped using the takeoff time board with those hooks, pesky tags, and rubber bands to keep them from blowing away?

No starts before 15 minutes after the last launch became the rule? When Designated Launch was introduced, the gate still opened with the first takeoff but there was talk almost immediately about changing it. I recall a day as late as 1982 where a bunch of the early launches escaped a storm at the Elmira 15M Nats while much of the field was still on the launch grid. Poetic justice was that the early starters glided out into a dead sky and the later launches were the only ones to get away.

Feeling old.

Chip Bearden
JB