Based off the SNB's index showing the real effective exchange rate for April

The index reading is one adjusting for inflation, and the reading is at its weakest level since 2011. That should at least give the SNB some form of comfort and breathing room in terms of interventions.

But complacency is a dangerous thing, particularly now that the euro is considerably much weaker and with EUR/CHF falling back below 1.1900 overnight. While the SNB should be comfortable with EUR/CHF sitting between 1.1900-1.2000 as of now, they would surely not want to let it run too far below the lower end of that range I reckon.