I frequently ironman, and I never reset for every death (even in 4 Kings, with full deployment, I let like four people die because I couldn’t be bothered to reset).
Generally on my first playthrough of a new game/hack I’m not going to ironman unless the game is really easy, because it’s easy to get the run killed due to one poorly explained map (maybe super strong reinforcements show up when you didn’t expect, maybe the chapter objective was misleading, maybe a new unit’s weapon/skill doesn’t work the way you thought it did, etc.), and it’s dangerous to let too many people die, because you don’t know how the lategame is designed and if you’re going to end up softlocking yourself.
Usually on subsequent playthroughs I ironman.
While I respect Pandan’s perpective, I don’t really agree with him that ironman friendliness is about minimizing the punishment for each death. For example, one of the few hacks that I have successfully blind ironmanned (well technically my first run died in chapter 2, but my second run was blind from Ch3 onward and was a success) is 4 Kings Deposition, in which every playable unit is a game over condition. By a definition of “minimizing the punishment for deaths”, this is incredibly unfriendly to ironmans. But in my view, ironman friendliness is all about reliability.
I see LTC and ironman as opposite ends of the spectrum of optimal FE play. LTC is about minimizing turns at all costs, usually involving resetting/rigging until extremely improbable chains of events work out in your favor (some LTC’ers do try to factor reliablility into their strategies, but when you go for the more reliabile strategy over one that saves turns I think you’ve moved slightly down the spectrum from a pure LTC (which is not bad, I don’t think there’s a “correct” position on this spectrum)). Meanwhile ironman runs are about maximizing the chance that you clear the game without losing, no matter how long it takes (just like with LTCs many actual ironmanners do care to some extent about turncount or avoid what they would consider “grinding”, meaning that their runs slightly closer to the “turns” end of the specturm than an ironman maximizing reliability at all costs (personally I like it when the map design inherently limits the amount you can grind for XP, so that maximizing reliability requires not taking forever)).
One of the reasons I like ironmans because they encourage me to find strategies that are reliable from turn 1, instead of, say, going for YOLO warpskips and resetting if I fail to kill the boss (or just in general being recklessly agressive early on and resetting if it doesn’t work out). In my view, the big thing that makes a game bad for ironmans is having a map (especially in lategame) where you are forced to rely on RNG to win (this is one of the reasons I think FE7 is a bad ironman game). If you have a green unit with, say a 90% to survive until the player reaches them, that’s not too big a deal in a regular run (although it’s still not great design IMO). If the green unit dies, the player is annoyed, they reset the chapter, they probably succeed this time, they wasted a few minutes. But if this happens halfway through an ironman, the player has lost hours of progress, because of the fact that there was no reliable way to beat your map.
This can also happen when your maps are so tightly designed that you expect the player to make a particular attack with <100 hitrate, and they’re basically screwed if they miss. In a regular run, if you miss a 90 that your strategy was relying on, you get annoyed, you reset the chapter, life goes on. In an ironman, you can lose the run. An ironman friendly game shouldn’t have chapters that rely on the player hitting a specific attack unless that attack has 100 hit (and maybe not even then). This is another area where I feel like 4 Kings is actually more ironman friendly than people give it credit for. The buyable skill books in preps are huge for boosting reliability, and the large open maps give you ample room to retreat and regroup if you miss an attack you really should have hit.
I’m intentional refraining from including negative examples of ironmanability in hacks here since I don’t really want to call anyone out, and I don’t really want to start an argument over games that I’m sure others in the community know better than I do. But my point is that if you want to make your hack friendly to ironmans, I think that the most important thing is making sure that every chapter can be beaten with a very high level of reliability by a player who is willing to sacrifice some turns/side objectives/characters for that reliability.