First, I am not sure that drain can't be healed with this trick. The way I see it, the source of damage to the second guy is "transmit damage" not "drain." But I am not going to argue the point because I -know- for a fact it will derail the thread. The only reason I will agree with you is "balance" and abuse.
Also, I am not sure what you guys are talking about wrt to apposed test. If I don't want to dodge a blow, I don't have to. There is no reason the adept has to put his full strength behind each punch when transmitting. He only wants/needs to do 1 point. Is it a called shot if the dwarf puts his hand on the table and tells you to punch it? Can I miss?
I see a number of applications for this trick:
1) Your troll takes 12 phys damage after armor, and you kill the bad guys. After first aid, and healing, you get it down to 4 hits which need to be healed by time alone. You then use this trick to distribute those 4 hits among the party and heal them 1 at a time.
2) A high end hospital has such an adept on the staff. When a vip comes in, this trick is used to get him on his feet within minutes. Then damage is distributed among the nursing staff, and healed 1 point at a time

Last point about abuse: Maybe 2 powerpoints and 1 spell is not a cheap price for a combination that has zero tactical benefit; except for the benefit of speading up the campaign. I mean what do you guys do when the elf is hospitalized for 2 weeks. Do you fast-forward the world? Do the rest of the players go to the time-sensitive adventure while you tell 1 player to go home?