I believe it is the Didache that exhorts Christians to receive the Eucharist making the “right hand a throne for the left to receive the King of Glory” or words to that effect. It would seem to me that one could make one’s left palm then a “diskos/paten” or “chalice” of sorts to hold the crumbs after consuming them. An open palm would just create issues with spilling.
Of course, in the East all communion is given through intinction. So we do not have this issue of communion in the hand, even though it is an ancient and worthy Christian practice.
The Didache also speaks of taking the residue (not crumbs) from the Eucharist remaining on the lips after receiving the precious Blood from the chalice and anointing the senses. I have personally adopted this practice over the years.
I think we need to be vigilant in our care for the Eucharist, without descending into either carelessness or scrupulosity. Our Lord has condescended to become Bread for us. I think He knows the risk of that!
Peace,
Gordo