Thanks for your reply! Given that feedback so far has been positive about option 1, we are considering moving forward with it and will have more updates soon, including on timelines.
With regards to the gas fees, with a very conservative estimate of max. 5 mill gwei for the entire migration (all transactions included) we’d be looking at around 0.006 ETH per user or a little under $8 at the current exchange rate of ~$1300 / ETH.