Originally Posted by
plhought
I used these at a previous operator.
https://www.seatpack.net/
You don't need a 9g bulkhead or any of the other special cargo aircraft accoutrements. The cargo being carried isn't supposed to really weight more, or use up any more room then the self-loading-freight would.
O.K., I get it now. I went back to the Original Post and see that the O.P. is just asking about some interim measures involving little or no structural modifications. I think it could be safely done, but as Icehouses pointed out, the loading/unloading would be awkward and slow. These challenging times require innovative responses.
Cheers,
Grog