Why Does a Lot of Pastry Have an Orange Flavor

This is because you are using a microwave. In theory, if you could turn off the microwaves in the microwave oven, you could use the convection function to bake things. In practice, we have had several questions which indicate that this is not how convection microwaves work. They keep nuking your dough, making it inedible. In your case, they are cooking all the moisture locally, resulting in mini-steam-explosions which create blisters, and a dried out, hard and crispy dough.

I am sorry, but there is no way you can bake with a microwave, not short pastry, and not other things. One exception might be quickly eaten "microwave cupcakes" which don't have much flour to start with and are baked for a very short time. I have seen people claim that they work, but never actually tried them.

For baking, you need a non-microwaving oven. The cheapest solution is a toaster oven with a 30x30 cm inner size, they are somewhat trickier to use than a big oven, but good enough for a small budget.

I think it's because freezing tend to dry things out. At lukewarm temperature, it's still 'steaming' a bit, which means evaporating liquid, so losing moist. If you can stop the drying out process at that point, the pastry won't be as dry as when you let it cool completely. Of course, a too high temperature can do harm to already frozen things, or would cause condensation in the package, so that there would be ice formed.

This could be the reason, and therefore, the statement can be true.