Changing the thickness of stems while keeping the glyph size locked

I want the feature to change the thickness of stems while keeping its horizontal or vertical glyph size locked.
The details are as follows:

Could you add this kind of feature?
Or do you have a similar plug-in?

It would be very helpful for making chinese characters unrelated to X-hight, descender and ascender.

Thank you for your consideration.

That is on my list.

Thank you for your reply. I’m looking forward to it!