I have desire to contribute, as using gas is not what i like and this
is fasm forum, my place.

Hm, seems it is better effort to just translate fasmg into aarch64, I want mention my name, Thomas is this ok, I don't want no benefits,
just for sake of altruism?

I also advised Apple to release specs for Matrix coprocessor, we should see if they will do that.

OK, I'll just do it. Then give credit to Thomas, as translation is just translation.

https://github.com/tgrysztar/fasmg/blob/master/core/license.txt

... is the license Tomasz has been using. In short, you should include the license with your modified version. I see no reason that you cannot also license your own work in addition to the stated requirements, but I am not a lawyer.