I've just submitted v3.2.0 of the Bootstrap-4 Template for the Zen Cart moderators' review; I'll post back here when it's available for download.

This release contains changes associated with the following GitHub issues:

#87: Include "More Information" sidebox in mobile-menu, if enabled.
#93: Use loading="lazy" to lazy-load images.
#96: Screen-reader updates for reviews' rating stars.
#97: Correct javascript/jQuery error on address-gathering pages; missing #stBreak.
#98: Correct missplaced </div> in products' listing template module.
#99: Adding an AJAX search; template settings are now in their own configuration 'group'.
#100: Add product-listing default grids for 12-column and 9-column center sections; enable the listing's 'grid' layout to be overridden.