You can change that 10000 ceiling by setting the MAXSEARCHRESULTS
property. You can set it on the module installation, see https://redis.io/docs/stack/search/configuring/ like:
loadmodule ./redisearch.so MAXSEARCHRESULTS 100000
or at runtime on the CLI or via your client like:
127.0.0.1:6379> FT.CONFIG GET MAXSEARCHRESULTS
1) 1) MAXSEARCHRESULTS
2) 10000
127.0.0.1:6379> FT.CONFIG SET MAXSEARCHRESULTS 100000
OK
127.0.0.1:6379> FT.CONFIG GET MAXSEARCHRESULTS
1) 1) MAXSEARCHRESULTS
2) 100000
127.0.0.1:6379>