In addition to what
@Blythe93 told you above, I have a feeling you just hate to update your Switch, am I right? You're probably afraid to break something, and I can understand that. If you only want to update once more, and never do it again, I would suggest you wait a bit more, until the next big update from Nintendo (20.0) comes out. And even then, wait until all the homebrew you use, Hekate, Atmosphere and sys-patch all get updated and certified to work. Only then, update. If you can live without playing the latest games for a few more months (and it looks like you can, as you're on an old firmware), that would be your best path. Of course, if you're comfortable updating, go ahead and update now to 19.0.1.