I suspect the ilClan era is an attempt to bridge the IS/Clan tech divide. We'll see how it goes.
And as far as 'infuriating designs' goes, I still hold a grudge against improved jump jet designs.
Speaking of infuriating things, my own grudge is with how many things are called "improved X" these days. It's an artifact of the game never retiring equipment since all eras must be playable at all times, but it feels so fucking stupid when you see a 'Mech with half its loadout being labeled "improved whatever".
If you can't think of an original name for whatever variant of some equipment you're creating, at least do it like the X-Pulse and Re-Engineered Lasers and tack on a unique word to their name.
Well, you could argue that those WarShips use some advanced future space magic that works with much more compact and sturdy radiatiors tucked away partially along the hull.
On the other hand, you could just fluff it in a way that during combat, WarShips fold up their fragile radiators and instead use some internal system to dump heat for some time, before that system gets overwhelmed by the excess heat of the reactor.
Then there's the option to remove heat by having coolant flow past the reactor and then just dumping that overboard from time to time.
Of course, all this means is that WarShips live on borrowed time during combat and can only engage for a short duration before parts of the engineering section start to melt.
Would make for a neat system tbh.
Also, can't remember which sci-fi-setting it was, but I remember ships extending their radiators during battle was akin to raising a white flag to surrender. BT could take a few notes here.
I would argue that BattleTech would be much better served focusing on what it does best and what its players and fans are most interested in: ground battles (including air assets). Space warfare, particularly hard sci-fi space warfare, can be a fantastic subject for a boardgame. Unfortunately, BattleTech does not make it justice in terms of rules or fluff.
Rules-wise, they tried to apply the same principles from 'Mech and ASF combat to DropShips, JumpShips and WarShips, and it just doesn't work. Once you have a vehicle that large, you're really worrying a lot more about having internal systems destroyed piecemeal (and thus relying a lot more on redundancy) than you are worrying about ablative armor and through-armor crits. The rules in Strategic Operations are an order of magnitude more autistic than the default rules, meaning that you might as well be playing a space battle in real time by the time you're done calculating and noting down everything for a single weapon being fired. And, of course, for practical reasons the game must be played on a 2D plane and that pretty much invalidates any attempt at realism in space combat.
Lore-wise, space is and will always be the final word in higher ground when it comes to hard sci-fi. Once you have ships that can perform orbital bombardment (in BT that's anything with Naval-class weapons), ground combat becomes a matter of pin-point police actions instead of army-on-army clashes. There's a reason WarShips were already extinct during BattleTech's early days: with JumpShips being glorified space ferries and too valuable to risk in combat, DropShips were the largest fighting units available. And while DropShips could be ridiculously well-armed (and effectively serve as Final Bosses for ground campaigns), they still used the same weapons as 'Mechs, so they couldn't just stay in orbit and shell things. So you needed boots on the ground unless you were getting really creative with dropping rocks from orbit. The entire set-up was designed to allow for ground combat to flourish, including the Ares Conventions and the Succession Wars telling everybody that just bombing shit indiscriminately resulted in
everybody having a bad time. The return of the Clans and their shiny WarShips indirectly caused that element of the setting to completely break down but FASA and everybody else since
very pointedly ignored it because it's a game about stompy robots and they can't afford to let logic get in the way of that.
In short, the less space combat there is in BattleTech, the better. I don't like that either, I love hard sci-fi spaceships, but the setting is just not meant for them. No matter how much they try to shimmy them in without disturbing the other elements already in place like a weird game of Jenga, WarShips are better served as background elements and left as vague as possible.