Important: IANAL and I am commenting from my personal reading
In the case of Fuschia, I don't see any more restriction of end-user rights than Apache 2.0 would give you. The only real difference is this line:
> This grant does not include claims that would be
infringed only as a consequence of further modification of this
implementation.
That makes it clear if you make a modification to Fuschia, that infringes on a patent that Google holds, that you don't automatically get rights to that patent too. Apache 2.0 doesn't mention that, but it appears implicit to me as Apache 2.0 only gives you patent rights to whatever is in the source.
Not to mention that patent law explcitly does not accept independent discovery as a defence for patent infringement, so I doubt that Apache 2.0 has any defences for that. I also don't believe GPLv3 does either but I would have to read through it again.
In the case of Fuschia, I don't see any more restriction of end-user rights than Apache 2.0 would give you. The only real difference is this line:
> This grant does not include claims that would be infringed only as a consequence of further modification of this implementation.
That makes it clear if you make a modification to Fuschia, that infringes on a patent that Google holds, that you don't automatically get rights to that patent too. Apache 2.0 doesn't mention that, but it appears implicit to me as Apache 2.0 only gives you patent rights to whatever is in the source.