High enzyme concentration may result in star activity. Long incubation with BSA is not recommend. To obtain 100% activity, BSA should be added to the 1x reaction mix to a final concentration of 100 μg/ml. There is DNA-methyltransferase activity in presence of SAM. It is maximum at 48°C. In presence of 10mM MgCl2 enzyme both modifies and hydrolyzes DNA. If MgCl2 is absent enzyme modifies DNA only. And that DNA become proof against BslFI. BslF I also cleaves the sequence GGGAC(11/15). https://molecular-tools.creative-enzymes.com/bslf-i-item-79.html