You’ve done some great research and have outlined an effective theoretical approach to putting people on ice. However, ultimately the success of a cryonic procedure comes down to how good we are at repairing tissue. To thaw out a colonist and have more than meat, you need some sort of nanobot or other cellular repair technology that you can use on your patients as they thaw out. Here are the main examples of damage you would need to treat.
When you freeze your patient, the most obvious (and acute) source of damage to the body is the formation of ice crystals. Large-scale tissue structures are mulched, cell membranes are blown apart, and even delicate internal structures and proteins are disrupted. As anyone who has thawed and cooked a frozen onion or hamburger can attest, the act of freezing and then thawing results in a noticeable change in texture and flavour (and a significant loss of fluids as everything drains out of the now perforated internal structures).
I'm listing this one for completeness' sake, but you have a solid theoretical way of avoiding this issue. So with direct mechanical trauma solved, what else is there?
There are a great many molecular structures in a given cell that are delicate and energetically intensive to maintain. While reducing temperature reduces chemical activity, there is some debate as to how cold you need to get before the more short-lived molecular structures in the body begin to degrade. When your cells are warm enough to engage in homeostasis, this short lifespan is an asset. If it is cold enough to stop biological activity and inhibit chemical activity however, it becomes a liability. These chemical springs will certainly uncoil less quickly, but they will still uncoil. ATP will dephosphorylate, RNA will slowly fall apart, etc.
Theoretically, you could get around this by freezing people down close to absolute zero, but that’s a challenge even on Earth where heat is a lot easier to get rid of than it is in space. I would imagine a compromise is made here, finding a minimum feasible temperature that balances reduced the decay damage (and repair/thaw time) with the machinery needed to keep everyone frozen.
We contain quantities of radioisotopes of carbon, phosphorus, and other elements. These are constantly decaying, and your body is continually repairing this damage. However, if you are on ice, radioactive decay will continue (it doesn’t particularly care about temperature) but the repair systems are now on hold. Damage from radioisotopes such as C-14 and P-40 undergoing their usual decay will accrue throughout the body, both in the form of the beta particles released and in the form of a generally rather important phosphorus suddenly being calcium and carbon being nitrogen, with knock-on effects for the molecule or protein it is a part of.
It’s worth noting that these are both quite stable radioisotopes with long half-lives (10^3 years for C-14, 10^9 for P-40), but we contain a lot of both, and both are incredibly important wherever they are. Carbon is the backbone of essentially every organic molecule, and the change in electronics and available covalent bonds from C to N presents pressing structural issues. And with phosphorus, it's almost worse: each nucleotide in your DNA has two of these, one joining it to each of the nucleotides on either side. Neither are great atoms to suddenly not have, and then there's that beta particle I mentioned - it's also highly likely to find a new friend in the area.
So, damage will accrue beyond the initial freezing. Ultimately, what your society will need to make this viable is a solid foundation of cellular repair technology, in whatever form that takes. Nanomachines are generally the most popular take here, and if you are spending three days to freeze someone, spending another three to infuse them with repair bots as they thaw out seems pretty reasonable. This does mean your setting has access to healing nanobots, which will have knock-on effects on human lifespan, disease, and what exactly constitutes ‘serious injury’ and ‘long-term treatment’ if most injuries are curable by a day or so on the slab while the nanites work.
I’ve done a surface level discussion of these topics, but if you want more depth I would recommend a couple YouTube videos by Isaac Arthur, a physicist and futurist, that discuss this topic. One is more general information on Cryonics (he focuses on the societal aspects of the technology and its uses but also gives more details on limitations), while the other is more focused on sleeper ships like your use case.
Cryonics: Frozen Civilizations