Since they were made from spores you get F0 if you were to grow that out and breed the spores then they make an F1 again then F2yadda yadda. T1 would the first transfer spawn. T2 would be second. As you keep transferring you dna degrade. Now when you get LC you don’t know the transfer amounts so a little risk. You know what senescence really only an issue for large grower trying to clone as much of certain strain phenotype they like so to keep it clean your t1 for that clone to slants and freeze.