I have a loadout closely identical to this here: https://karl.gg/preview/17069#/, so let me point out a couple things:
You don't really need that extra damage from the Cryo Cannon's tier 4A because you're already freezing things adequately from tier 5B's Cold Radiance and still deal increased damage. More ammo from tier 4C is better.
The extra 50% charge speed is fast enough in that you don't need tier 3B. Go with tier 3A so you can get off 7 more charged TCF shots.
I tried running your suggestions and have decided to keep my build as it is. T4A feels a lot better to use than if I run T4C due to the convenience and speed of which IS kills bugs. I also find that T4A balances out the ammo of T4C as the sheer damage from it kills bugs quickly enough to not consume too much fuel whereas the latter requires more usage, therefore practically evening out the fuel consumption ratios (albeit the T4C one is definitely a little better).
Additionally, the EPC is similarly being kept at 3B purely for its convenience, as the thaw time of some of the larger bugs can be a little finicky with the timing of the charged shot.
Ok, for secondary I would choose smth that is independent of temp shock (bc temp shock for cryo storm is... kinda excess, as long as you use T5B for freezing and OC increases damage vs. frozen very much). If you want to temp shock, use smth except of cryo storm. So, as for secondary I'd choose 12322 EPC with Heavy Hitter. When you need to kill praetorian, freeze it with cold radiance and kill with axes or EPC.
The temp shock is really for the more beefy targets and I find it really useful as such. That being said, I might test out HH and how it performs with IS. Thanks for the suggestion.