Remove Cryo Tanks and use Helium-3 for cryo coolant

[next basin]

In rocketry, it is standard for cryogenic fuel to be used as a coolant in place of any additional coolant.

In the context of cryogenics, such as for superconducting magnets used in fusion reactors, helium-3 outperforms helium-4 due to its lower boiling point.

Source:
https://trc.nist.gov/cryogenics/Papers/Heat_Transfer/2008-Calculated_Regenerator_Operation_at_4_K_with_He4_and_He3.pdf

Concerns people already raised or might have:
"But you're already busy burning Helium-3 as fusion reactant!"
You have tens of thousands of kilograms of helium-3, you can spare a few hundred kilos of He-3 for coolant, assuming you even need that much.

"What if you run out of coolant because you've burnt it all for fuel?"
If you're out of coolant, you're also out of fuel. If you're out of fuel, you don't need coolant.

[dense shard]

this seems like a tech difference that could be a different strategy or approach to cooling - you pick one or the other, maybe. Maybe this is a more expensive or rarer solution out in the boneyard, but the more advanced ships made by people who well understand the engineering and science may use the more realistic (using h3) solution

[next basin]

Well, you see, just running a separate line from the He-3 is easier and cheaper than having a second tank.

As far as I’m aware, Helium-3 don’t behave too differently from Helium-4 other than the lower boiling point allowing for more efficient cooling at near absolute zero temperature.

Also, what’s Tritium(H-3)’s go to do with this?