Survivability of Mortal Wounds & Required Bed Rest

Wanting to figure out how survivable hitting 0hps is, I ran some numbers.
Assuming CON bonus of 0, 6hp total, no magical healing, no healing proficiency, treatment before the battle is over but not on the next round – here are the percentages:
Fine / Rest 1 Day / Rest 1 Week / 1 Day? / 1 Turn? / 1 Round? / Dead Already
0hp: 10% / 25% / 25% / 25% / 15% / 0% / 0%
-1hp: 0% / 10 % / 25% / 25% / 25% / 15% / 0%
-2hp: 0% / 0% / 25% / 25% / 25% / 25% / 0%
-3hp: 0% / 0% / 25% / 25% / 25% / 25% / 0%
-4hp or less: 0% / 0% / 10% / 25% / 25% / 25% / 15%
At first I though that looked pretty spiffy, but than read the small print and started getting these terrible doubts.
At level 1, before access to magical healing, 10-25% of the time when someone goes down they will recover without any healing – but will take a week to do so.
Even at higher levels, with access to magical healing, a required bed rest of at least 1 week is a fairly likely: all cases where the character survives conditionally on sufficiently fast healing require a minimum of 1 week of rest – which magical healing doesn’t shorten.
Hauling around buddies needing time to recuperate seems much more disruptive to dungeon crawls than mourning them and moving on – and introducing a new character is easily less disruptive than a lengthy period of required rest.
Am I missing something, or is this correct? If I’m correct, any suggestions re. tweaking this for my own use?
The simplest change would be to allow magical healing to always circumvent the need to rest, even if it doesn’t solve the issue for level 1.
Or am I just missing the game opportunities the required bed rests generate?

The required bed rest is intentional. Since most groups like to adventure with a full complement of party members, the bed rest creates downtime in town which can be used on magic research, magic item identification, finding and hiring henchmen, commissioning items, learning new spells, and so on.
Players tend not to begrudge a wounded comrade some downtime, but they will often complain if, say, the wizards wants 2 weeks to research a spell, or the thief wants to do a hijink. By coupling the two, you create an ebb-and-flow which is great for campaign play.
If you are just running one-offs or a convention game, you can of course shorten it to 1 day or whatever else is suitable.
PS One final beneficial side effect is that the process of leving begins to take a long period of in-game time. If each foray into the dungeon is followed by, say, 2 weeks of bed rest, then you’re getting 2 adventures per month. That in turn means that making it to level 6 (30 sessions) will take 15 game-months. 15 months is about how long it took the Red Baron to become the world’s deadliest fighter pilot. The much longer period of game time required to level allows for a greater verisimilitude with regard to the adventurers’ expanding role and place in the world.

In original D&D there is an explicit assumption that you will go on one adventure a week, which is partially reinforced by the rate of natural healing (1 hp per day) and more strongly produced by the two week recovery time from /raise dead/. The ACKS system is designed to do the same thing even for lower-level parties where resurrection magic hasn’t come into play yet.
It is quite true that introducing new characters will let the party continue more easily, which is also intentional. Playing OD&D, my group tended to argue for some possibility of survival after 0 hit points in direct proportion to how well-loved a character was. Negotiating that on a rules level wasn’t ideal; it’s much better IMO make this decision based on in-game factors that apply equally to all characters but may be more meaningful for some. This way individual players are able to say “yes let’s wait for Gleep Wurp the Eye-biter to recover” or “guys I’m eager to try playing one of the new Player’s Companion classes, leave Gimdor in town and I’ll bring in my new Shaman.”

Thanks for unpacking the thinking there for me. I’ll see how it goes before tinkering.