"while at" is a correct and usable phrase in written English. It is often used to indicate a specific point in time, such as when describing an event or occurrence. For example, you might say, "We met up while at the grocery store."
While at Helmstedt, Ger.
I think while at home.
For a while, at least.
Walker started performing standup while at Juilliard.
While at Kean University he played baseball.
No. Relevant experience while at home?
He is forcibly fed while at Ashworth.
While at work.
You represented tenants while at the Bureau.
Its founders, Mr. Vasconcellos, Emerson Andrade and Alex Tabor, met while at Stanford University.
While at university she sees a therapist.
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com