It is great to have the functionality to set up URL parameters for the Sidebar Instant App template. However currently, there is only the option for ONE layer to set for the URL parameter. It is important to have at least two layers available for URL parameters, which was supported functionality in Web App Builder.
This is important because it is an app we plan to share to the public on our website, and there are various ways we want to link from the website to the app, requiring URL parameters. We are also migrating our apps away from WAB and to Instant Apps due to accessibility and other reasons.