Hi,
I think this is a bug. Maybe not...
In the snippet call, when you set parameter like this
&liHomeId=`57` &loHomeId=`58`
we can see the default tpl before to be redirect to the page 57 or 58.
If you want to display directely the page 57 or 58 (not to see the default template before), in webloginpe.class.php, find this code in functions LoginHomePage() and LogoutHomePage() :
modx->sendRedirect($url,0,'REDIRECT_REFRESH');
and replace by
$modx->sendRedirect($url,0,'REDIRECT_HEADER'); // CREDIT: Guillaume to redirect directely