30mm (1.18in) is about the max you can safely lower... Best case is you lower the triple tree (raise the forks) an equivalent increment to maintain bike geometry.
I just lowered mine 19mm (3/4in) front an d back. Triple tree is almost touching the handlebars... When I lowered my 2013, I had to swap out the kickstand for an adjustable. On my 2017, for whatever reason, it wasn't necessary...there's still enough lean... BTW, I'm 5'9", 29" inseam, and the 19mm was perfect.
If you haven't ordered links yet, you might want to try Rick Richland's from AdventureTech (he's on this forum). He makes excellent links (better than stock), among other Strom products...
I posted pics of his installed links on my bike somewhere else in this forum...
2017 Pearl White 650[/B]
AdventureTech lowering links and GPS mount
AdventureTech +2" SS braided brake line
GPI spools, SW Motech risers
Givi XS307 Tanklock bag and Givi 46L top case
Suzuki hard case saddlebags