I think stairmaker should have kept for at least 2 or 3 versions from version 21.
In every on-going project we migrate there is for sure a stair to be modified ... in this case we have to re-model in AC21 from scratch ... it's time consuming.
eng. Alessandro Mandala - Italy
AC27 latest hotfix
Win 10 Pro 64bit
Double XEON 14 CORES (tot 28 physical cores) - 32GB RAM - SSD 256GB - Nvidia Quadro K620
Display DELL 2560x1440