You could use tubeless without sealant, but it'd be quite a gamble. But yeah TR is essentially a bit of a half-way house requiring more than regular amounts of sealant, which might be useful in the longer term. IDK.
No ones does though, right? Which is why most tyres are TLR. No point having added weight and rolling resistance when everyone is going to chuck in sealant anyway.
Do people every use tubeless without sealant? Or is "Tubeless Ready" just a way of justifying not having the liner?