Video Settings when Starting a Project Aren't Changed When You Export

I’ve been using shotcut for a while, and I’ve noticed that if you start a project with a low quality preset (lower res than the video you’re trying to edit) and try to export it a different resolution later on, the video will always export as the resolution you initially set when you started the project.
So, if I start a project with 640x360 15fps and export it at 1600x1900 30fps, the video always exports as 640x360, even if the source video is 1600x900.
I have found a solution for this: Open the project file in a text/code editor and change width/height to the width/height you want to export as and change frame_rate_num to the fps you want (multiplied by 1000).
But my question: is why doesn’t shotcut already do this?

What version of Shotcut are you using?

Windows 10
Shotcut version 19.09

Not quite sure how this is a bug.

This is how Shotcut works.

Set Video Mode, which you did by creating a custom video mode.
Open a source file (I used a 1920x1080 video file)
Export (by default it will always export the video mode set, or the Video Mode that is by automatic)
Since you want a different export option than the video mode you set, click on Advanced, and change the settings.
2019-10-12_04-25-37 MediaInfo_2019-10-12_04-16-15

Going from higher to lower quality does work.
However, this problem occurs going from lower to higher quality. Shotcut should definitely be give you a warning to change the video mode if you’re trying to export at a higher resolution than the video mode, if not change the video mode to what you’re exporting at.