Don't confuse "tack on" fouls with "live ball treated as dead ball" fouls. The former cannot be carried over to the try/kickoff, but the latter can.
Yes, penalties for all fouls by A on kickoffs or scrimmage kicks that cross the NZ can be added to the spot where the dead ball belongs to B. The exception to this is, of course, 5 and 10 yard penalties for fouls by the opponent of the scoring team that occur during a down that ends with a TD. And, personal fouls by B that occur during a legal forward pass play may be penalized from the end of the last run if it ends beyond the NZ and there is no change of team possession during the down. These penalties tend to be informally called “tack on” penalties. As you note, these penalties may NOT be enforced on a Try or subsequent kickoff, only at the succeeding spot where B will snap the ball for a regular scrimmage down.
Penalties for
live-ball personal fouls and unsportsmanlike conduct fouls, as well as LBFPADBFs (which are UNS fouls by non-players) by opponents of the scoring team during a down that ends with a TD, may get penalized on the Try or the succeeding kickoff/spot in extra periods. These penalties tend to be informally called “carry-over” penalties. Also, fouls by B during a successful Try may be penalized on the succeeding kickoff or at the succeeding spot in an extra period. These penalties also fall into the category informally called “carry-over” penalties.
Robert