Lets talk about cracks for a moment.
Cracks can be either active or passive.
An active crack, such as when the wood is drying or undergoing changes, i.e. drying/weather/humidity/saturation, will continue to crack until it's equilibrium point is reached then it will slow down but never truly stop as some changes can cause it to grow even more.
A passive crack is one that has cracked as a result of some traumatic event, i.e. drying, sudden drop in moisture content etc and is no longer growing. It is a weak point in the structure and should be addressed with some type of resin, bonding agent or similar.
Adding any type of glue/epoxy to an active crack will only break and damage the glue joint and cause more headache down the road. The only way to deal with active cracks is to rate limit lost of moisture in the wood by a controlled drying process, i.e. kiln.
Adding any type of glue/epoxy to a passive crack will strengthen the weakened area and build up the gap, UNTIL it turns active and grows more. Things like change in saturation point, humidity, weather, location and a slew of other things can cause this to happen.
Stabilizing helps greatly on passive cracks. It helps by securing the fibers with resin and allowing them not to absorb things like water, moisture, fluid and the like. This in turn removes the fibers need to move. Whatever is currently in the fibers will stay in the fibers forever and also hinder uptake of the resin. This is why tannins, waxes, varnishes, water and everything else needs to be out of the material before it is stabilized, else you are shooting yourself in the foot and causing more problems down the road.
When evaluating wood to be stabilized you need to look at several points and they are very vast to list every one of them but include weight of the final product, material harmonics, environment the product will be used, how hard/brittle/stable the wood is.
Hope this helps.
