Work for an airline and the pilots use electronic flight bags meaning all their charts, manuals, checklists, etc are on iPads. All of our planes have the items listed below or similar that suction cup the iPads to the direct vision windows. I use them to hold my airport map and checklist when I’m taxiing planes for maintenance and have never had an issue. I would double check all those parts are compatible and fit together correctly. Also couldn’t find one for the iPad Pro 11 and I don’t know what the size differences are. Might be worth a look though

Cicony RAM Mount Twist Lock Suction Cup Base Window Mount, 360 Degree Rotation https://www.amazon.com/dp/B07VSNK6CP/ref=cm_sw_r_cp_api_i_pr8iFbKJ6WESX

RAM Tab-Tite Tablet Holder for Apple iPad Pro 9.7 with Case https://www.amazon.com/dp/B0098QTFTO/ref=cm_sw_r_cp_api_i_cu8iFbDFYW75E

RAM Round Plate with Ball https://www.amazon.com/dp/B0000BVFUC/ref=cm_sw_r_cp_api_i_sv8iFb47RVY0Q