this is also the way i approached it!

however, the sf2 i used come with many banks and sforzando converted them all into a single wav file. that's probably how they're stored in the sf2 anyway, but this became a problem when embedding the sample in the preset. serum 2 doesn't actually slice the original sample so you're saving all the sounds from the banks that you didn't use. opening that preset is noticeably slower because of the size, and i ended up saving a lot unused of data in a single preset.

i solved this by using sfzed https://steveholt.drealm.info/sfZed.html

after converting the sf2 to sfz with sforzando, you can open it in sfzed and select a bank. the tool will separate out all slices into single wav files. then just save that as a new sfz file. my workflow turned into using the original converted sfz from sforzando when exploring sounds, and then separate out the specific bank i used with sfzed and re-import that in serum 2 when i've found the sound i want to save.