How many miles on your bike ? You could be due.
SAMCO makes such good sense, many captains have just installed them on general principles.
In practice, flat hoses usually are a sign that the system has been under pressure, and when cooled, something contracted. It's not a problem generally, as when you run, it'll be back at full pressure. Still, would be good to check all your connections -- perhaps remove the radiator (an easy do) so you can see everything - if you park in the same place, check for leaks. Breaking the connections to remove the radiator, you'll want to pay particular attention to the bleed procedure in the manual (and can be researched on this site).
The system is designed for the expansion and contraction hence the overflow tank. When hot, the fluid can expand into that tank, and when cool again, the resulting reduced pressure can draw the fluid back, and in the process, see your "flat" hoses.