It's single player. If you want to camp the map edge knock yourself out. If it bothers you then stop. The same way you choose to save scum or not, or to edit your save file to give yourself 20 paragons or not. It's up to you to manage your game experience as you see fit.
I never tried edge camping so I may be wrong but to me it already sounds like it has sufficient tradeoffs. Yes you can't be flanked but you also can't kite back to vent or to maneuver so it can be very bad if you are pressed by a strong enemy. I've had some battles when I ended up pressing the AI against the map edge and it went very badly for him. Well obviously it was going badly as it is but after they got pressed against the map they all ended up clumped together, bumping into each other. Also unless you camp the corner you can in fact be flanked at the edges of your formation where the enemy can mass locally superior forces, where as in a center of the map deployment your formation can shift around to respond to enemy movement.
Ultimately I suppose the viability of this strategy is mainly a matter of fleet style. If you like to roll around with Onslaughts and Dominators then it's probably very strong as you say. I usually prefer lighter faster fleets that need to move around to win. Especially my flagship will almost always be an overgunned cruiser or capital with a mobility system that relies on hit and runs and venting. Something like a DME Kormoran or a Blackrock Nevermore.
You are partly correct, but to me it's mostly an AI limitation. Enemy fleet AI doesn't really understand that the tactic is being used and
wants the surround if it has and needs more ships (in its estimation) to beat the fleet in front of it. Because it doesn't realize that's impossible or at least detrimental to attempt, many ships hold off attacking and trickle in to die when they try and flank. This is compounded on by the fact that the player is very aware of what they are doing. Especially while piloting a mobile ship, they can just wait for that opportunity over and over again. Its the equivalent of camping in a room with a single door holding a shotgun in FPS games. Without grenades, no experienced player enters that room if they can help it. Its suicide. The AI can't make that decision and just jumps into the meat grinder.
And that's not even getting into how carriers can capitalize on this strategy even more efficiently.
I'm not saying there are easy ways to solve the AI's problem with this, but I would definitely classify it as an unintended exploit.
Just stop doing it?
Right, single player game and all, but still kind of a bad argument for not fixing an exploit. That's a little like saying "just ignore colonies because they give you so much credits and it makes the game easy, we don't really need an endgame to balance that out." Sure, you
can do that, but the second you find yourself truly in a challenging situation that has long term financial consequences (like the game intends) you will likely be sorely tempted to give in. Why is that different than something like imbalanced mods or console commands? I'll try to explain:
Many players can compartmentalize the difference between what the game intends and makes available vs what mods or cheats (console commands) can offer. Its two different categories of content and so, psychologically, you as the player kind of "bought into the imbalance" of the second category.
When a player is playing for the first time (golden experience) they expect something a little different. The bar is higher for balance because its "cannon" design and so exploits in that arena are harder to ignore because they can sometimes feel intentional (since the dev didn't feel the need is the assumption as to why it wasn't fixed rather than they just didn't catch it which is likely more often the case). That's why even in single player games exploits (or obviously overwhelmingly efficient play styles) are often patched out later in the modern gaming era.
Back in the days when you couldn't do that as easily (cartridges, etc) the games with bad or numerous exploits were often just considered sub-par to those without them. It seems easy to just ignore them, but when your reward in learning is so often tied to achieving better prowess at the game, knowing you are ignoring "supposedly intended" (again the assumption the new player often makes not my personal opinion) and far more optimal strategies- just for what they would consider a better balance to the experience- is almost always off-putting.
EDIT: Oh almost forgot:
I think as @bobucles said that a heightened ppt drain around the corners would be pretty easy to implement and make the tactic less efficient. Like the shotgun in a room example, if you can you starve them out. It also gives a tangible effect to track in the combat layer that could actually be hooked into the AI.
Player ship in this zone? Don't follow them (put an Ignore order) and only assign fighter strikes, etc. That would be a lot easier than trying to get the AI to be tactically aware of a tactic like that.