Regarding the QC pipeline (constants) found in mirtrace

[RJEGR]

Although (tentatively) srnas < 18 nts may correspond to ribosomal or transfer RNA fragmentation (Axtell, 2013), it would be desirable to include additional flags to input different values for MIN_ALLOWED_SEQ_LEN parameter. In especially since the mirtrace-stats-length.tsv output usually shows read sizes distribution < 18 nts but without offering additional information about their homology-based origin.