Courts are typically reluctant to grant sole custody without documented basis. I think risk to the child might be one of them, probably depends on how it is quantified and other factors. One downside is that something isn't generally deemed 'actionable' until it happens.
What does sole custody mean to you? Custody often refers to the legal end of things such as major decision of medical, school, religion, etc. On the other hand, a parenting schedule impacts the day to day parenting and care.
Ponder parallel strategies. Seek sole custody but also work with your lawyer on how to implement backup strategies such as Decision Making or Tie Breaker status. In practice, DM or TB are effectively sole custody with a twist but not in name. It allows the other parent to not feel totally shut out. At least that's probably how it is implemented.
While full legal custody is optimal in high conflict cases, Tie-Breaker or Decision-Making are close seconds and easier to get or keep. While sole custody feels so much better, there's not all that much difference, here's how the concepts work in general terms:
Sole Custody
Make decisions and inform other parent as appropriate
Decision Making
Make decisions and inform other parent as appropriate
Tie Breaker
Ask other parent, if tied then proceed and inform other parent as appropriate
Typical Joint Custody
If no agreement on a major issue (medical, school, religious, etc)
then parents turn to mediation, court, etc.
As you can tell, there's not all that much difference. So if you can't get sole custody then advocate for DM ot TB. Something is better than nothing. The ex can always take things to mediation or court, just as you can. Of course, sole custody is safer and more likely to withstand sabotage, but many courts are reluctant to award sole custody to one parent, they prefer not to declare a Winner and a Loser. So DM or TB are more palatable all around, court likes the nonjudgmental middle ground, ex saves face and you get to proceed with minimally sabotaged parenting.
