There is a Federation fundamental that no penalty is greater than 15 yards so I believe it is their intent that the penalities are 15+15 instead of one 30 yarder.

X. PENALTY MEASUREMENT
1. The distance penalty for any foul may be declined.
2. Penalties are either 5, 10 or 15 yards.
3. Any live-ball foul is penalized according to the all-but-one enforcement principle except:
a. Fouls which occur simultaneously with the snap.
b. A foul by the opponents of the scoring team during a successful try, field goal or touchdown
when the score is accepted.
c. A nonplayer or unsportsmanlike foul.
d. Roughing the passer when the dead ball spot is beyond the neutral zone and there has been
no change of team possession.
4. Penalty enforcement for any dead ball, nonplayer or unsportsmanlike foul is from the succeeding
spot unless the foul occurs on a scoring play and the scoring team chooses enforcement on the
kickoff per 8-2-2, 8-2-3, 8-2-4 or 8-2-5
5. The penalty for any one of the five illegal passes is a loss of 5 yards and the down is counted except
for a forward pass following change of team possession.
6. The penalty for offensive pass interference includes the loss of down.
7. No penalty directly results in a safety, but if a distance penalty is enforced from behind the offender’s
goal line toward his end line, it is a safety.
8. The penalty for a live-ball foul by the defensive team is administered from the basic spot, except
when that spot is in the end zone.
9. The loss of down aspect of a penalty has no significance following a change of possession or if the
line to gain is reached after enforcement.

So then they didn't get rid of all the contact USCs -- or they did, and later brought one in.

Another interesting aspect is that this is an exception to 9-9-1. In other codes an intentional pass interference that saves an obvious touchdown could be penalized equitably by the award of the score, but in Fed this special 15+15 penalty (however it's administered) is clearly "specific rule coverage" which supersedes the equitable penalty.

In theory, I suppose you can award a score under NFL rules for an palpably unfair act, but realistically, that rule is mainly used for interference by non-players.

In a high school game in VA... After a TD play there were two sepereate dead ball unsportsmanlike penalties and the referees kick the ball off from the opponets 30 yard line. Never seen a kickoff from the opponets 30 before that night.

if they didn't try an onside kick they are stupid.

Try the 10
 

High school game with 4 penalties assessed on the kickoff. They kicked from the R 10 yard line. They kicked it OOB at the 4 hoping that R would accept the 5 yard penalty and force them to rekick so they could try an onside kick. The only other option they have at that point (no 25 yards from where the ball was kicked) was to accept the play - which they did.