We have transitioned from an onpremise Sharepoint to SP Online, this type of task is very necessary in many migration instances not just our own. Copy and rename, using a formula, that is all I need. I can tailor a script but lookups do not work properly unless done in a very specific order. Try doing that will 200 sites and several thousand lists. I cannot stress the level of necessity it is to dynamically remap changed list lookups. PLEASE ADD THIS TO THE NEXT VERSION OF SHAREGATE. But my biggest issue is that the support we get now is pretty bad. Its takes days if not weeks to talk to someone, and even then I get a 30 minute support call (with pressure to end the call if over 30 minutes). This is terrible support and it was not always like this.