My two cents into safety.
Let us be more specific. Shall we
Pit bike forks are from 500mm up to almost 800mm. You can choose length the same as dh forks, 730mm or 750mm.
Prices:
pit bike DNM fork about 300eu - 400eu. 735mm weights 6.28kg to be specific.
Faceace fork is simial in price and weight.
Above two mentioned pit bike forks are not worse in quality compared with DNM8, opposite, they are better for heavy bikes due ability to install pit bike brakes.
So let us add up.
Pit bike fork weighs 6kg
triple clamp 1kg (maybe this is included in the fork weight, can't tell right now)
front wheel 4kg (if you use 17 mc pit bike wheel) / (if bicycle wheel take put 1 or 2 kg)
brakes 1kg (yes, they are not high end but work better than any pricy dh brakes)
and little unforeseen stuff like axle or smth 1kg
Pit bike:
So, pit bike front end - 13kg overall. Probably you can do 11kg or even less if you use bicycle wheel.
Bicycle:
Downhill bicycle front end (fork, tyre, rim brakes) 6kg or 7kg or even 8kg if with mc tyre.
Therefore pit tike front end is not too heavy, especially if you plan to go fast, 70km/h or so.
Bicycle brakes are not sufficient for heavy and fast ebikes. Cheap rotors have not much metal and gets hot fast, some have cooled rotors but hey are still are too thin, brake pads have a small surface, wear out quickly.
In pic you can see pit bike fork.