Crossing / Knocking at/on door

Context: I have received a feedback request for an interview process. The company didn't offer me the job, but I appreciate their approach in requesting feedback, so I am inclined to provide it. However, I'm not sure it's anonymous and I'd like to express some criticism, but I also would like to not be excluded from a possible recruiting process in the future because of my opinions. I told someone the following sentence:

I am reluctant to express negative feedback to someone whose door I might knock on again in the future.

They (native speaker) corrected me saying:

... whose door I might cross ...

Which version do you prefer?

Thanks!

Solution 1:

“On whose door I might knock” is correct. It is better not to end with a preposition.

Native speakers don’t cross a door, at least in my neck of the woods, unless they want to give the door a special blessing.