Interesting topic, it's really hard to breed Chili Rasboras (in normal western aquaria conditions that is).
Apparently in SE Asia, Indonesia it is a thing to just throw some buckets of leaves in a big container, filled with rainwater and adding some Chilis, leaving it outside in the sun and voilà, after a few weeks it is full of fry of all sizes.
Only saw very few cases where people managed to get some fry in aquariums however. Supposedly that doesn't really happen above a pH of 6.5 and low hardness, although I know of one case.
Chilis are egg scatterers and will prey on their offspring. They only drop a few eggs a day however, further complicating things. The fry is so small, it can only feed on infusoria for quite some time. I've read suggestions to add enough leaves to grow a good amount of biofilm and microorganisms on, they will feed on that.
Check the Boraras subreddit on Reddit:
https://www.reddit.com/r/Boraras/
Have a look at the about page, the "Miniature Jewels" something article has some breeding tips too. Should also be able to find 2 or 3 posts from people that managed to get fry, explaining it.
Not exactly, Strawberries (Boraras naevus) are a clearwater species (from Malaysia) that live in 'harder' and less acidic waters than Chilis (Boraras brigittae) that are a blackwater species (from Borneo) that live in super softwater and acidic environments. (Also they inhabit slow flowing forestry peat swamp rivers with basically no vegetation, just leaves etc.)
Obviously they share a lot of characteristics being in the same genus (Boraras) but it's a wrong assumption that they're equally easy to breed imo (or that they thrive in the same environments).