There are a number of Down Air Mats that are reasonably light, but a PITA to inflate. The BA Pumphouse and the Stephenson's Stuff Sack leave a lot to be desired, IMHO. The Exped internal is OK, but weighty.
What comes to mind is a "squeeze box" style bellows, made out of 6" dryer vent.
Add simple coffee-can style lids to each end.
Install "flapper valves" into one, and attach a "connection of your choice" to the other.
Add some sort of finger loops so you can pull it apart. Or a foot loop and a hand loop.
Pull and squeeze, pull and squeeze, pull…..
Other off-the-wall concepts, improvements, suggestions greatly appreciated.
Hold off on the nay-saying.
Offer whatever you can.
There has got to be a better way.