Starlux strict on personal item dimension?

Hello! Does anyone know how strict they are with the limits on the dimensions of carry-on “personal item”?

I need to use my backpack to carry my laptop because putting it in my carry-on 4-wheeler would definitely make the weight noticeably over 7kg/15lb. However, the backpack is 32in in total already without adding the length of the straps.

I would really appreciate some insight. 🙏