Oval work really well with singlespeeds, I got into using them around 2009/10 when guys like ned overend and fuzzy mylne were racing on them. Rotor Q rings are still the daddies of elliptical rings. Absolute black are ok if you’re on a budget, but they are made of cheese.
The rule of thumb for SS elliptical is to go two teeth up over a round, so if you use a 32 go to 34 oval. you can swap like for like, but like your mum used to say if you were wearing a coat indoors “you wont feel the benefit”
set the chain tension with the crank at 4 O’clock and then you wont get any chain drop issues.
Ovals help to smooth out knee bounce at very high cadence when you are spinning your titties off and at very low cadence grunts up climbs help to get over the dead spot.