The company can make involuntary STVs not applicable by:

Make the Expat package better. At almost no cost to the company they could 50% match housing costs above $2700 up to the IRS housing exclusion max.

Make Voluntary STV's worth while by offering an incentive pay of 25% or make the bid lines 90 hour (4 week) or 110 hour (5 week) guarantees. The additional hours are about what the company would pay in deadhead hours for a 1 month STV (assuming they plan on paying DH hours).