Often I run into cache issues when I modify e.g. a stylesheet or javascript file, and it doesn't get reloaded in the visitors browser. This could be avoided by adding a version query parameter on assets links, which forces the browsers to reload the asset.
Right now a link tag looks like:
<link href="/_themes/mytheme/css/mystylesheet.css" rel="stylesheet">
by using:
{{ theme:css src="mystylesheet" tag="true" }}
The solution could be:
{{ theme:css src="mystylesheet" tag="true" versionquery="true" }}
and then the link tag would be:
<link href="/_themes/mytheme/css/mystylesheet.css?v12348589" rel="stylesheet">
The version query parameter should by a sanitized string of the last write time on the file.