Importance of E-Verify in labor force for subcontractors?

There is a subcontractor business that I am looking at that serves a particular niche in the construction industry throughout the US, including a heavy presence in Florida. According to the owner, they follow the guidelines provided by the law but do not currently E-verify every employee. He has said that he is willing to E-verify his management staff, but nothing beyond that.

I don't know what I don't know... should I be concerned about this, particularly given the changes in E-verify requirements in Florida? Would you consider this a risk-to-manage, or something that could elevate to the level of deal-breaker?

Any insights appreciated. Thanks!