Not specific to the individual kit, but generically to the process, here is my experience with using older kits for e-6.

First developer syrup is pretty stable and will loose activity with time.

I mix my FD from a jug of kodak 6 step makes 25L FD syrup expired dec 06 at about 10% over the spec strength these days, to compensate for the activity that has been lost in the mix since it is old. The syrup has stayed in plastic, but with the air squeezed out since openning it 4 years ago. The over rich mix was found via trial and error with test strips of macbeth charts and a densitometer.
Your mileage may definitely vary here. I started out by eye, and that worked fine but I wanted to be more deterministic.

Do not over -use this mixed bath, or keep it half used for a long time before running it again to exhaustion.

Kodak Reversal bath sems to be stable in storage, but I don't trust it after mixing and replenishing it sporadically for more than 4 weeks. If the volume has been good, I rinse well pre RB, and then optically re-expose part way though the RB to be sure and stretch it to 8 weeks with optically good results.

Colour developer may come in two or three parts. The part with the colour developing agent will work well past its expiry date if that syrup is transferred to full glass containers, and kept in a cool temperature stable place.

Once it goes black it has gone off. Being left partially full is likely to cause this. A $1 worth of washed dollar store marbles solved this problem for me.

Colour developer I use and replenish per spec, and though old, it seems to work just fine for me.

Pre bleach concentrate I have found to be stable in concentrate form. I have a surplus of it, so I don't try to stretch it's working life.

Bleach comes in a and b sometimes, or just a single bottle other times. Oxygen is it's friend, and I have yet to have bleach syrup die.

Fixer concentrate can sulfate out just like all other ammonuim thiosulfate based fixers.
Mixing a diy one with a pH suited for colour is a solution if this happens top the stock syrup.

I rinse well with two baths between bleach and fix to extend the effective life of the mixed fixer.

Wetting agent I have never had go off.

I hope these comments are helpful, regardless of the kit you ae pursuing.