Advice to increase the accuracy asked for mapping

[wdesaintjean]

Hello, thank you for this very impressive aligner.

I have a question about the parameters for mapping:
I use minimap2 to map nanopore RNAseq reads on genome and use the standard parameters.

minimap2 \\
        -ax splice \\
        -t 16 \\
        index_genome \\
        $fastq > ${meta.id}.sam

But I have alignment on a gene that I know it's not transcript in some samples. I want to know what parameters I can change to have less alignment on this gene, to be more selective. I try to increase the penalty by mismatch (-B), but I want to know if you can give me other advice.

Thank you for your help,
William