So I just checked this on the sandbox, and it seems to work fine. Granted I was an admin. If it keeps getting stripped, you can do something like this.
<a class="telephone-link" data-tel="1234" href="#">1234</a>
and then you can use the jQuery and enrich the <a> with a selector like $('.telephone-link').attr('href',.....) and pull the telephone number from using .data('tel') and set the value of HREF.
Hope that helps.
Great. Thank you. I will give it a go.