Multi-account browsers are actually built for exactly this kind of workflow. Each profile runs its own separate session so you can be logged into completely different accounts at the same time without any of them interfering with each other. Worth reading up on browser session management here: https://gologin.com/blog/browser-session-management/ . Once you get your head around it you can have all your clients’ accounts open at the same time and just switch between tabs like normal browsing.