Maybe I misundertand the term, but I thought "press kits" all use blix, not bleach and fix. Blix is specifically what I was wondering about anyway, and because the blix starts attacking itself right away according to posts here, I assume it was the first to go bad in blix kits.
Good point you mentioned Wayne !
Blix - so what about blix ???
Blix is nothing others than a mix from 2 solutions. You have a bleach solution and a fixing solution. Next step is you are mixing both (and have a strong hope it will work fine ....




)
The manufacturers are mixing the names and so - simsala bim - they made (from bleach and fix) BLIX ???
And (no wonder about) it still works - indeed it does.
But there are some doubts if it is the real best way.
To me the point of quality is not the main issue with blix (some real experts are not amused about characteristics with blix - in concern of long live stability).
To me it is sad to have it not seperately.
If you have a bleach wich is still working but your fixer is exausted it is easy to change the fixing solution.Most it is the opposite direction (fixer does still work but bleach has to replunish)
Special to replunish the bleaching solution there are interisting ways to do this (depending on the type of bleach).
And we may notice : bleach is priced priced higher and higher.
So replunishment of bleachin solution is the best way to save money - by the way : you may also save the envirement by replunishment.
And don't forget : bleach is a real bad chemical.
With blix there is no way of replunishment - afaik.
Last issue : c41 procedure don't know blix. (But manufacturers create this method to make their kits more attractive) - by saving a batch step.
But if you just have a blix : you might use it - it is not an existential problem

.
At last - caused you asked about - the live of working (blix) solution.
No it isn't the way you descripe - blix isn't the solution wich become first bad.
Often the CD is the part wich make trouble after a time first.
And allways it will be the part of bleach within your blix wich will not work correct after a period of having in use.
But then you have to waste all (also the fixing part wich may be still ok).
Thats not very smart from my oppinium.
with regards