Sadly:
both implementations, rscheme and chicken where found to hang completely upon
httperf --hog --server 127.0.0.1 --port 2009 --uri / --ra 60 --max-connections=4 --max-piped-calls=10 --num-conns=1000
with a rate --ra > 20 if, and only if, the page containts sqlite read requests.
In a way this looks as if it might be either a sqlite3 bug or one in the glue code.
Though it was fixed at least for chicken within short time.