Transaction Launchers in Upgrades

Hi partners, I would like to solve a doubt, I don´t find the answer in any forum. If I want to upgrade my SAP CRM version, what kind of customizings and operations could I lose while upgrading the actual version of SAP CRM? Would I lose all the configurations made about transactions launchers in Web UI? I have read this post but I cant find the information I need.

SAP CRM EhP3 Upgrade

Thanks above all.