I’m also in-between on this one, but leaning towards supporting a deadline in the future.
The benefits of a deadline is less supply, in addition to that, a more active supply. You can safely assume all AAVE in circulation is fresh/active and likely not in dead accounts or forgotten about. On top of that, it brings us closer to leaving LEND behind and moving forward with AAVE.
The downside I think, is what everyone else is probably thinking, what about people who may not have known about the migration until it is too late. What effect could this have on the protocol? To me, it just seems like users could be upset or lose money because they weren’t aware of the migration or deadline in time, which is the main/only downfall I can see.
I think one approach I’d lean towards is after the migration has reached a certain point (60-70% migrated as others have suggested), we could set a deadline after that migration amount is met. But even doing that, I think there should be proper steps taken to ensure every LEND holder that can be possibly notified is notified, for example, MetaMask warned users about having SAI when it turned to DAI if I remember correctly, similar with Uniswap - so what if we could reach out to these providers to warn users still holding LEND that they’re able to migrate?
Just thinking out loud here.