Most comfortable maternity leggings/yoga pants?

I own and operate a dog walking and pet sitting business. In PA, we have had ridiculous heat and anything with a waistband has been making me very nauseous, so I've been wearing cotton sundresses and flip flops to walk dogs. Orthopedic flip flops from my podiatrist.

I am having the absolute worst time with my feet. At 20 weeks I am barely hobbling along at this point and the pain is non stop. I've tried ice and epsom salt with lavender oil soaks. I've tried elevating them. I am going out of my mind with foot pain at this point so I am going to try wearing pants so I can wear sneakers with orthopedic insoles.

I need to know what you love about your leggings - and what you hate so I can order some. I'm looking for the least constrictive option possible. Help!!