I have tubless ready 20" rims (299g 35mm OD wide, and 330g, 40mm OD wide), but always too lazy to try and no sealant.
Also always drilling F/V presta to A/V auto and usin a tube to build the bike quickly and go out.
A/V valves with thread are available, so I might try one day once I get new tires. Wondering if thick tires like BSD will be easy to seal with compressor and how they wilk hold the air.
I did some getto tubless on mtb 27.5" with basic Shwalbe tires (non tubless ones), just rotated and shaked the wheel few times in 24h, the sidewall was leaking some tubless milk, then sealed completly. It was working.