Post-release "clearance by rote" is - as this terrible accident strongly
suggests - a seriously flawed methodology.

I agree. I aways turn right after release, to satisfy the rule, but only maybe 30 degrees before halting the turn, and turning back left as necessary to keep the towplane in sight. The towpilot necessarily loses sight of the glider after release, and should fly directly away from the release point until well below the release altitude.