Just go run missions, those give you a reason to be on the move, hit the nav beacon in every system you drop into, then that will tell you what every single signal source is, look for high grades and detour to them. It doesn't really matter too much WHAT g5 materials you get from the HGE's you stumble upon as you were just in the area doing something else anyways, so the mats are a bonus, and can be PX'd at a material trader.
Whereas if you go seeking out the perfect alignment of system allegience, bgs state, pending states, distance from star, and go specifically hunting for a particular mat, its going to feel like it took you longer to get there, and will lead to frustration if the HGE spawns the wrong material.
Since you are looking for HGE's, you are obviously on the look out for materials, best doing cargo delivery missions. I'd suggest you fit out a combat capable python cargo delivery ship with collector limpets, dirty drive thrusters, 6c biweave shields, collector limpets in the smaller module slots, cargo racks in everything else. Weapons, very subjective choice, frags and railguns is what my mission runner is carrying, but its up to you.
Go stack half a dozen delivery missions, but because you are in a 180t cargo python, you can only carry one at a time, and theres a reason for doing it this way. Since you very often get pirate NPC's targetting you, moments after you get message from mission giver with "incoming enemy alert" and a bonus to kill them. The enemies are of course the ubiquitous Elite Anaconda* - so go 4pips shields and fly rings around them, frag the frack out of them, and with report crimes on you'll get cops drop in to help you, and strangely enough other hostile NPC's from other missions you've stacked, even though that cargo is still at the originating station. So you end up with this surreal little mini personalised CZ with two or three elite NPC conda's on one side and you plue a few cop vipers on the other.
Those little mini CZ's that develop with multiple mission related NPC's and the NPC cops are actually quite fun, and when the dust settles, theres a tonne of materals for your limpets to feast on, and you pick up a couple of million credits between the bounties and mission bonuses. Then theres the mission hand in which can often offer materials, take them. You probably haven't got what you wanted, but you will have ample mmaterials to swap out at a material trader to get what you were after, and you've had fun playing the game rather than getting bored and frustrated finding HGE's.
Another good source for G5 manufdactured materials is "pirate lord" assassination / wing assassination missions, those are nearly always Elite Federal Corvettes, and when those things die they leave behind core dynamics composites.
Thank you for the tips. I've tryed the mission way to, but it seems they only give Biotech conductors and Exquisite focus crystals.
Passenger mission is a good tip, I'll eventually try this the next time I'll do those missions.
Still however I would prefer to have a more reliable method to farm directly those tons of different materials. Overwhelmed how things are complicated and not enjoyable.