1) We do not yet know how many charges are available. If we "blow the wad" before achieving our objectives we have not only wasted our opportunity, we have also made it virtually impossible for the miners to perform their primary tasks.
2) We do not yet know if it is possible to achieve at least a truce with the ETs.
If I were occupying the tunnels and suddenly discovered a strange machine and its friends, I would be upset and likely to believe I was in danger. If those friends started setting off explosions in my tunnels, I would be convinced I was in danger and would take ANY action I felt necessary to eliminate the threat.
Until we know for certain that we are dealing with an entity that cannot or will not behave in a non-hostile manner towards the probes, I do not agree that a provacative act such as "carefully placed explosions" is a good idea.
3) We do not yet know if there are bigger and badder weapons that have not been used upon the probes.
4) We do not know the effect upon the tunnel structure of setting off the charges. I doubt that any of the probes are programmed to perform the calculations necessary to determine a safe location for such a terroristic act. The programming of the miners, on the other hand, is likely designed to achieve a form of cave-in which is not at all what we really would want to do.
My vote is to hold that action in abeyance. It would be prudent to have the resources prepared and in place (as much as possible) but DO NOT proceed at this time.
Koala, Captain, Team Andrew