I am wondering if it was possible to create some sort of custom patch for the app "Driverslog Pro 2".

Since its possible to get unlimited 30 day trials maybe you can reset the date the app thinks is true somehow. Over the classic ways (in app purchases) I wasn't successful with any patches. 

I am a long time user of lucky patcher but lack the technical knowledge to try this myself. 

Until then I will just uninstall and reinstall the app every month ^^

Kind regards, Tobias