I've found two examples of DWARF expressions in the wild: 1. A handwritten expression in libpthread <= 2.19, which was removed in 2014 [1], and 2. the expression covering the PLT section of most binaries. [2]

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=1157194#c14

[2] https://github.com/mstange/framehop/blob/6777199dd0c2c1b3768...