Strange behavior of equilibrium constant when most of the components are solids / pure liquids

Consider the reaction $\alpha A(g) + \beta B(s) +\gamma C(s) +\cdots \rightleftharpoons \delta D(s)+\epsilon E(s)+\cdots $, so the chemical equilibrium constant should be $\dfrac{1}{[A]^\alpha}$, which is only dependent on the concentration on $A$. However, if I throw in a huge amount of $A(g)$ into the system, then it's possible that at least one of the reactants will be depleted before even reaching the equilibrium. So I have a few questions:


* Is my deduction correct and does this situation exist in reality?
* And furthermore, in more extreme scenarios when all the reactants and products are solid or pure liquid, then is the reaction still considered *reversible* since adding anything into the system won't change the reaction quotient and any state can be considered as an equilibrium?


