No - The accordion-style containers are not as good as purported to be. I have had problems with them with basic B&W chemistry. The plastic is not high grade and is porous enough so that the chemistry degrades over short periods of time.
Ilfochrome chemistry does go bad, especially the developer. I have three unopened P3.5 kits that are no longer usable. I have read (maybe an old APUG post) that they have a shelf life of 2 years.
I have resorted to 'schedule' my Ilfochrome printing. I stock up on materials and then set aside several days where I print nothing but Ilfochrome until my chemistry is finished. Unfortunately this is not always possible - everyday life tends to get in the way...
Is it my imagination or was the first Cibachrome chemistry available in powder packets?
The concentrate is good for 2 years, the working solution in a full stoppered bottle is good for 2 months and the working solution in a 1/2 full stoppered bottle is good for a month. This is from the literature that comes with the P30 2 liter kits.