I am looking into using Salmon, but I need to quantify immature transcripts. Salmon examples I have seen all use a transcripts.fa file made of mature transcripts. I was thinking to make a custom transcripts.fa file that includes unspliced transcripts. Is there any reason why this would be a bad idea? Is it likely to be accurate for for very long, but relatively low-abundance molecules, such as unspliced/partially spliced transcripts?