The following needs to be verified in order for this epic to be considered complete: Perform a differential update from current v6.1LTS (9.4) to add the Maple-Tree VMA iterator that was left out due to performance and correctness reasons; Perform incremental updates to v6.2, v6.3, v6.4, v6.5, and v6.6 in order; Verify each incremental update (KT1-lite  + MM regression beaker tests); Bring up follow-up fixes from upstream's v6.6 longterm branch;