What is to see on a pressure meter inside flash-freezing water in outer space?

The question is specifically about flash freezing but let me mention anyway the video by Derek Muller about water slowly freezing, in which case it makes no material difference whether gravity is at play or not.

The water cools down from the outside in, so the outside freezes first. The water trapped inside then finds a way out, and as that water makes it out to the surface an ice tube tends to form. The phenomenon is called 'ice spikes'

Flash freezing

So: a blob of supercooled water in zero-G, and you do something to trigger freezing.

We can scale that up, and make it a massive amount of supercooled water. The flash freeze must be triggered at some point, either inside or on the surface. From there a freeze front will propagate.

At that point I see a problem: as the water freezes there is a corresponding release of heat.

Some time ago there was a question here on physics.stackexchange whether a kilogram of ice can be cold enough to freeze a kilogram of just-above-zero-C water, if you bring the two in contact with each other. It turns out ice cannot be made cold enough to do that. The end result of the calculation was that even if the kilogram of ice was close to absolute zero at the start, the heat absorbing capacity would only be enough to freeze about 0.9 kilogram of just-above-zero-C water.

So in order for a body of supercooled water to flash freeze it must be sufficiently far below zero C to absorb all of the latent heat of freezing, which will be quite far. But a body of supercooled water is unstable. I assume flash freezing can be triggered by a random quantum event too.

For the sake of the thought experiment let's assume that the massive body of water can be supercooled to a sufficiently low temperature.

A freeze front will propagate. Let's say the flash freeze is triggered from the center of a spherical mass of supercooled water, so the freeze front will be an outward expanding shell. Let's assume the freezing comes with the known volume increase. So the freeze front has to do work. The freeze front has to displace the outer water. Because of the inertia of the outer water the need to exert a displacing force will give rise to a (transient) pressure in the ice.

Of course, once the seismic effects of the water displacement have dissipated the pressure will come down again.