@MPLantarón in my personal experience I was taught that it is ok for extension lines to cross and that the only gap was from the starting point. After talking with the Civil and Plant support they have had previous experiences where their managers had asked them to do it with gaps on certain projects. If someone has a current ISO manual they can reference and confirm that would be helpful.
As for Inventor doing this behavior, I don't know that it has the built in feature. A good post for the Inventor Ideas if I'm not proven wrong.
A terrible headache of a workaround... create a Sketch Symbol with Symbol Clipping enabled. Make the middle line standard, make the outside lines a custom layer as white.

Create a vertical and horizontal version and place over every instance.

it plots in the pdf like you want...

I cannot imagine doing this for every dimension cross, but if you have to and need it to be done, there you go. Hope this helps.
Please select the Accept as Solution button if a post solves your issue or answers your question.