Yes, plasma accelerators still exist with reduced thermal load secondaries. FD can simply add a heat reduction to the experimental mods if they choose, exactly the same as they did for railguns in the new system. That is not an argument to remove all prior legacy mods.
Which would also be acceptable fine for me, despite it yet again being power creep.
The point here is that those small changes are mostly relevant for PVE, or simply to provide some interesting variety, and certainly don't break the game.
It is relevant in several ways. First i can once again point you at legacy PAs. While i am not a PvP player, i fully understand that those low-heat PAs make a massive difference for a PvP setup. The next important aspect points in a whole different direction: currently any new player at some time has to learn that there's equipment in game, which he will never get, no matter how hard he tries. And some of the equipment, e.g. PAs, also is PvP relevant, so not just a beauty of PvE issue.
And i guess this is also the point where we never get together. We view the thing from different aspects. Everything you post is along the line that you spent so much work in a computer game and should thus permanently now have an advantage about everybody else in the computer game.
I rather look at the state of the game and how it looks for a new player. The fact that it's impossible for even the most dedicated new player to ever fully catch up to a veteran, even if now only logs in once a month to show of his shinies, is discouraging. We already know that ED has a steep learning curve and has rather low player retention. We don't need additional artificial constructs to discourage people to stay.
So yes, i could also just egoistically threaten doom whenever somebody ever things about getting things in order. Yet i'd be ready to give up my artifacts of old time, which are better than anything you can now create, for the health of the game.
What you're not getting here is that a ship engineered entirely in the new system would be substantially more powerful than one that relies on legacy mods. Take my FDL as an example. Using the best G5 dirty drive tune I could produce under the legacy system it boosts at 500 m/s. If I take the new G5 dirty drive thrusters from my Mamba which are maxed out in the new system and put them into my FDL it boosts at around 550 m/s. That makes the new system for dirty drive tuning at least 10% better than what I could produce using legacy mods. The blueprints for weapons are even more powerful, closer to 15-20% higher dps. Overall a ship built entirely with the new Engineering system is at a substantial advantage overall, around 10-20%, in all areas. Could you reproduce a prior legacy build exactly? No, but you don't need to as the new maxed-out blueprints offer around 10-20% better overall performance.
If we're now on the level of "not getting" something, i can also say that you did not get what i wrote. Nowhere did i say that my courier is all-grandfathered. But congrats for the nice strawman of "all legacy vs. all new system" you built there.
I pointed out the legacy power plant. The rest of my Courier was rebuilt on the new system. Yet thanks to that -one- grandfathered power plant, my Courier is above and beyond what any new player could ever achieve. It's not that they would not try hard enough. It's not that they would not be smart enough. It's plain and simple that my power plant is better than any power plant is as a spot which the present system can not reproduce.
I rolled that one like 50 times till i was lucky. In the new system, i can easily build a power plant which has the same or even higher power output, at the price of much more thermal load. I can also build one which has slightly better power output and similar thermal load, at the price of adding several tons of mass. But i can not reach the same spot of power output and reduced mass while still maintaining the low thermal load.
And that's unfortunately also something i had to tell to some of my friends over the Xmas period. During that time, they decided to take a look at the game again, learned about engineering and how i did things. And each of them reacted negatively when i told them that reproducing my Courier would be impossible for them.
But alas, i guess we just have to agree to disagree. We just see things from different perspectives.