Well the last unit to already loads in courses but the last course does not gets saved anywhere from which we load it .
In v3 we have direct links from curriculum : https://wplms.io/support/knowledge-base/direct-unit-link-from-curriculum/
what you can do is to save the course status unit url in usermeta on unit_travese trigger .
https://wplms.io/support/knowledge-base/run-custom-actions-on-unit-load/
$('.unit_content').on('unit_traverse',function(){
//while this runs you can get unit specific url in course status in url bar
//make ajax call to save window.location in usermeta
});
then after login you can fetch this usermeta and simply redirect user to this link .