This is an unofficial solution to customizing the text of the client portal links. In the snippet below, you can add multiple calls to the "renameElement" function with the first parameter being what the nav says today and the second parameter what you want the nav to say.
function renameElement(fromName,toName){
var elements = document.querySelectorAll('.nav-label');
var targetElement = Array.from(elements).find(function(element) {
return element.innerText.trim() === fromName;
});
if(targetElement){
targetElement.innerText = toName;
}
}
setTimeout(() => {
renameElement('Invoices','Bling Bling');
renameElement('Time worked','Clockin-in');
},100);