My kimchi bubbled happily on the counter for ten months, no issues. People really overestimate how easy it is to mess up lacto-fermentation at home. Just keep everything under the brine and trust the process.
Used to worry about leaving stuff out too long, but seeing a ten month kimchi still going strong makes me rethink things. Guess it really is more forgiving than I thought.
Yeah, room temp works great for the active ferment. The only catch is that stuff left out for many months can get real soft (still safe, just a texture thing).