Status: mechanically submission-ready; manual organizer review of the learned recurrent-program boundary remains required.

U5d preserves U5c's learned automatic choice between Montgomery and short Horner. It replaces U5c's oversized categorical clock tables with the exact compact learned clock representation already validated by v23, transfers the compact v20 arithmetic modules, and evaluates only the Student operation emitted on each turn by the learned Teacher.

The checkpoint has 414,490 parameters, compared with U5c's 8,483,476. Its short adapter reproduces 263,169/263,169 U5c operand choices and 513/513 U5c initial clocks. Initial raw Tier 1--10 evaluations score 200/200, followed by 100/100 after strict reload. Randomized weights score 0 correct on 74 nonzero answers.

The final packaged candidate passes manifest validation, static analysis, preprocessing isolation, determinism, and the full official four-CPU sandbox. It scores 1,000/1,000 scored Tier 1--10 cases in 88.8 inference seconds. That is 55.8 seconds (38.6%) faster than U5c's comparable 144.6-second run.