Ah. Preview features are not intended for use in “production” apps as they are more likely to contain bugs and are not well supported. Normally, I would encourage you to post your complaint to the post that announced the feature:
I see, though, that the post is owned by “anonymous”, which suggests the original poster no longer works as an AppSheet developer, so isn’t monitoring the post and won’t respond. You could try contacting Support to report the problem, but based on my experience with Support, that’d be a frustrating waste of time. Instead, let me call out to some AppSheet team members in the community who may be willing to offer guidance: @Adam-google, @Aleksi, @Jose_Arteaga, @amyplin