It would be really nice to be able to centralize all the engineering in one port. For example, once a CMDR has unlocked all the engineers, it gives it a license or whatever to be able to do ALL the changes, including experimental effects, at one port. This will be more convenient for those who have taken the trouble to do the engineers, but also to try things, improvements etc.
There are several things you can do to do minimize the number of trips you need for visiting engineers.
For most of the common module engineering you are likely todo, pinned blueprints are the way todo. so you can get the biggest effect without having to pay any engineers a second visit. And this makes the two most commoon reasons for visiting an engineer to be add experimental efffects or change pinned blueprint.
For example Felicity Farseer, do FSD, Thrusters, Sensors, DSS, Shield booster, FSD Interdictor, Powerplant. So a single visit to Felicity will allow you put Experimental effect on FSD, Thrusters, Shield Boosters and Power plant! Then you use Remote Engineering to upgrade these modules to the level you want. So not many visits are needed for these modules.
For weapons the situation is a bit different. but here there are many more viable options,So pinning a blueprint is more likely to top of the upgrades remotely once you have added the experimental effect, so what is pinned are likely to change based on what you trying out.
Because if we want to make a super engineer, that can do all of the stuff, why should we need to hike around half the bubble to gather engineering material? with the same logic, lets put all the needed material in one location as well... now I know that a few would think this would be a brilliant idea, but if we do that what reason would there be to even collect material the current way? or even care about mission rewards or material traders? And now we can ask why even have engineering in the first place? why not simply remove it completely? and all of these things would be a non-issue.. except that many ships would be unable to function, if we removed all the engineering from them them.
If you view a thing in a negative manner, you will most likely have a bad experience doing it. if you try to have an open mind and thinking how to incorporate this in your playstyle, you can get enjoyment from this. Players tend to be experts at finding the most efficient way todo something, and thus missing what could be a fun part of the game.