Tyramine is not an MAOI. Tyramine is the amino acid that one must avoid if one is taking irreversible MAOI drugs like Parnate, because it creates an overabundance of dopamine in the body when the MAO enzymes are disabled.
Chocolate is an excellent carrier for mushrooms because chocolate does NOT have MAOI activity to any appreciable level. Mushrooms should keep their potency (within 80% of original strength) for at least one year in the freezer, regardless of the form (whole mushrooms, powder, honey, or chocolate).
My personal favorite storage form for mushrooms is in honey. Simply grind the dry fungus up and add to a jar of warm honey. Stir in a teaspoon of ascorbic acid (vitamin C crystals), teaspoon of ground ginger, and teaspoon of ground cinnamon. Freeze or refrigerate as necessary. One teaspoon of the mixture usually has about 1.5g of mushroom material in it (obviously depends on the ratio of fungus to honey that you used), and dissolves fairly quickly in a mug of hot water for "instant" mushroom tea with flavorings already added! Or lick a spoonful like a lollipop if you enjoy the flavor of ginger and cinnamon. If you don't like the flavor, the cold honey forms a lump that is easily swallowed like a pill.