E6L9 hard from scratch without the first secret (& "essentially mandatory" secrets discussion)

Have you ever done it (the first secret referring to the one that is to your right at the start)?

I have done it using only that secret an no others (which includes no secrets in the Fatface room either), but I have not yet done it without that secret. There are too many guards, you don't have enough ammo, and you have no cover (keep mind mind the only health or ammo in E6L9 is in four separate secret areas, aside from ammo dropped by fallen enemies). But I could envision it being remotely possible, albeit insanely hard, to go without the first secret if you were to use extreme patience, precision, and also have simply some good luck. So has anyone done it?

(Nonetheless, despite the fact that I don't see it as being outright impossible, I'm reasonably sure that when ID made the second room the way they did [a huge four door attack], that was meant to be [at least for scratch starters] more or less a dead giveaway that the first room contains a secret. I'd say if you're scratch starting on hard that secret is all but mandatory.)

As a second question, as far as I know, only boss levels (and in particular, those on Episodes 1, 2, and 6) contain "essentially mandatory" secrets, that being secrets that are not in the technical sense absolutely mandatory secrets (like E2L2, E3L8, etc.), but rather secrets in which you would have to do something extreme to survive without. This is considering every level on hard starting from scratch. Using these parameters, do you consider any secrets on non-boss levels to fall into this "essentially mandatory" category, and if so which ones?

I already mentioned that I've done E6L9 without secrets, starting with pistol eight rounds, but with saving. (On hardest difficulty)

First open the left-most door, try to kill one or two guards. Move back to starting room, hot-foot it back to the right most room, killing another 1-2 on the way. Open right-most door, killing another 1-2. Pop back into starting room, careful, officers could be behind you. Take them down. What you want is a SS to die. If you can get a SS with only an officer, you've basically finished the level. (Well, all the most difficult bits.) The trick is, for me, moving to both ends of the room across multiple doors, popping in and of the second room when it's time to do so. Kill as many guards as you can each time you open that door, and when you run to the other door.

I would not say is' EXTREME if I were allowed saves, because it took me less than 10 minutes. (Maybe 5, but probably less than 10). It goes without saying, conserve as much ammo at the start as possible when you take down the guard/two officers. If you're having trouble with ammo, at the start, once in a while, you can kill the guard with one shot. (Or possible knife it at the cost of being hit once, but there is a chance the guard will barely deal damage even on hardest.)

When I say extreme it's not all about time. It's about how precise and meticulous one must be in order to be successful. First you have to "peak in" to the four door attack room trying to alert only one enemy. You have to try and guide said enemy to the correct door or else a chain reaction is triggered and the whole room goes boom. Repeat this many times. Then in the areas with the steel centers you have to alert one or at most two guards at a time, lure them back to the start room or the four door attack room, and make sure that door to the silver center room is NOT open. If it is, one shot will alert everyone except the Officers in the small alcoves. It isn't easy to control enemies opening doors so it's best to do one at a time so you know once the door has closed and you see the enemy it will remain closed. Again ONE mistake shot and you have no chance against the enemies that will be at once alerted.

This process clearly resembles what a very hard puzzle type level may be like, and far from what you are expected to do in any original game map. That and the fact you will take an incredibly long time to do all this is what makes it extreme. I'm not saying any requirement for strategy is extreme; but I feel it's fairly obvious ID wasn't intending on anyone doing it this way.

That's true. But one mistake problem isn't a problem as much if you can save. Likewise, I'm unsure if I'm able to do a perfect speedrun of any episode because I'm unable to save. ID software granted us with like 10 save slots.

The no saves is part of the challenge. Sure if you save after every success you can eventually do it. But there are others who play without saves. Most video recorders do.

I have not seen that level donoe with those restrictions done on youtube before. I can attempt it, but I'm currently busy with work, and at most I can record me starting the level without saves - (not doing level 1-, but even that's kind of a stretch.