The sim service provides access to a precomputed all-to-all blast search, so I don't think it will help for the query you need. I've been exploring/testing the idea of using blast for the Translation service, to be able to map sequences or gene calls to features of a specific genome. I can say that blast is installed on the kbase images (including tblastn), so it is easy to call from a kbase service, but it is not yet wrapped as a general kbase service as far as I know. That said, you could take a look at the
blast_tester.pl in the Translation repo or the implementation of the map_to_fid method of the Translation service for an example of how I'm calling blastp and creating a blast database for a specific genome.
let me know if you have questions on this.