I'm bringing this one back.
Was trying to figure this out myself.
I received a couple of flat patches of fissiden "thailand" nobillis awhile ago from overseas.
The geppi I initially got was from AFA in San Francisco, I believe they imported it from Japan.
Initially, I thought they were different because the thailand had a red stalk. Now that everything has grown out the red stalk disappeared.
Then I thought they were the same after seeing the thailand grow out.
Finally, I took a closer look today. The thailand fronds are a tad bit smaller. Probably a unnoticeable difference if you aren't looking.
Either way both/same are ridiculously slow growing. If I took a picture you probably say it's the same.
Hope this helps!
Bred and grown in the USA... Mostly! Proud member of SFBAAPS!