Been using a "composting" toilet for 2 years now.
I did DIY. The store bought toilets are quite frankly bad.
One,they cost too much for what they are .
Two, so difficult and gross to clean.
And no one REALLY composts do they? Probably not.
I went with a urine separator and 5 gallon bucket,toss the bag once a week. Takes less than 5 minutes to empty and clean.
I've also found a "medium" is absolutely not necessary. The TP and baby wipes are sufficient to conceal the poo. Since you're probably not really composting, it's just an unnecessary cost of $ and storage space.
Good Luck.