the answer to this question is to either pon the

to get

wait or ignore the tile and aim for riichi. I prefer to pon the

in this circumstance because it is already around the 8th discard and the average tenpai speed is around the 10th discard which means if you don't pon this

you might lose out on speed in getting to tenpai. another major reason to pon the

is that the

is the dora which give you a possibility of getting 3900 points which is high enough to ignore the potential of getting riichi in my opinion but ignoring it for riichi is also a valid option as a hand that is waiting on a dora can be hard to win + the probability of achieving tenpai within a few discards is quite high.
However if this was between the 1-4th discards, you should probably wait as the probability of you being able to tenpai before everyone else and riichi is quite high. around 5-10th discard is debatable but anything after the 10th discard I think you should pon. However I do stress that it's not necessarily wrong to wait 'forever' as some people prefer because I think it all comes down to style of play but the one Ive listed is generally my preference in play.
(if the

is not the dora, I think you should still pon but the timing gets a bit more debatable due to difference in play. I will probably pon around after the 8-10th discard but anything before that i might wait in this circumstance. If you need a mangan tsumo, then you should wait even after 10 turns and if you need a quick hand, I will pon before the 8 turn but in this circumstance it's still early and the point difference is still close so I will say a border at around 8-10th discard is probably right. This also applies to when

comes out from anyone.)
I've also ignored

chi because it limits the max. points to 2000 and you have two tile less for the wait ( two tile makes ALOT!! of difference). (5 tiles vs 3 tiles)
I will also note that you can also choose to keep the

you've discarded in the turn before and thrown the

instead. The advantage to keeping the

is that you get more chance of getting a double sided wait and is considered a more efficient approach in winning the hand rather than just prioritizing to get to tenpai. Consider

, the total number of tile to tenpai (ignoring any discards because i cant be bothered to count) is 42 tiles off 13 different types of tiles but out of the 13 different tiles only

(only 5 different tiles(total 16 tiles))leads to a double sided wait (a good wait). If you discard

instead of

instead, you get

which has 37 tiles off 11 different tiles to go to tenapi, but out of the 11, 7 different types of tiles(total 21 tiles)

lead to double sided waits or good waits. increasing your chance of getting good wait at tenpai can overcome the advantage of more tile to tenpai and particularly in this case where

is the dora, discarding

instead of

increases the chance of your wait including the dora which leads to higher average point score assuming you win the hand. If the

was

, discarding

instead becomes more advantageous as you increase the chance of pinfu and drastically increase the chance of haneman tsumo as well.
if the

isnt the dora, if you choose to keep

, you should throw away

just to increase the chance of all simple or tanyao and therefore increase the average expected points gained for the hand.
You may be confused to which you should choose but the general rule is if you are oya or the parent or whatever you call it, you should prioritize tenpai just because riichi is really strong when your oya, but when your the child, you should prioritize the probability of getting better wait as if you riichi and if the oya riichis after you, your more likely not to lose. There are more specific rules that I use but i cant be bothered to explain.
Should the 2 riichi sticks + honba on the table affect your decision?
the answer above completely ignored the riichi sticks and the honba on the table, but if you have 2 riichi sticks on the table, the balance leans more towards ponning the

than ignoring it. I would probably pon as early as the 5th discard if i could but depends on your style of play.
What if you didn't have the red 5?
this makes a difference and leads further towards ignoring the

due to the much higher score that can be achieved via riichi than opening your hand.