I think there might be a typo. 30,,,38
I have an Haibike Yamaha and i experience no problem.
Day 1 i switched the 11-36 cassette to a 11-42 than 2 months later i switched the 175 arms to 165 and just positive results. Let say your cassette is 11-42 you could probably switch to an 11-46. You can adjust your derailleur to not have access to one of your extreme cog just to test for free in just minutes easy to undo. If needed check on youtube how to do that. Are you trying to extend your range?
Are you trying to improve your fitness level?