workhard: I did look at several rail-mounted saddlebag supports on the market but none of them seemed to work with sprung saddles, such as my Brooks B67. Seatpost-mounted saddlebag supports, although can be used with sprung saddles, cannot be installed on Strida. 
If anyone here knows of a rail-mounted saddlebag support compatible with sprung saddles please kindly share the info with us. Lastly, I often go grocery shopping with my bike, therefore the ability to carry a shopping pannier is important to me. For other Strida owners rail-mounted saddle bag support can be a great option. Thanks for the suggestion.