Damaged Inner clutch

Replace it.
That looks like damage from not using the correct tools.

Paw Paw

Motion pro makes a clutch holding tool. Theyre cheaper than a inner basket

Easy answer – it should probably be replaced.

Is this totally necessary – probably not. Now before I get hated on for this answer, let’s think about things from an engineering standpoint for a minute. The steel plates make contact around 252 time with the clutch hub (assumed 7 steel plates with 36 teeth each; 7 * 36 = 252). Now put your clutch pack by in and count how many of those teeth do not make contact with the hub because of the missing piece that broke off. Judging by the wear marks in the hub, it looks like your missing only one point of contact but to show just how negligible this can be, we’ll just say it’s 5 for this example. Assuming 5 points of contact are now lost, you now have 247 points of contact with the clutch hub, which results in a friction force reduction of just about 2%! If one point of contact was lost, your friction force reduction is just 0.39%. These are numbers so small you’ll probably never notice them. A typical safety of factor in design for a component like this could be upwards of 10-20% so I would argue that you’re well within the acceptable range. Also, the loss in frictional force can easily be recovered by slightly increasing the torque on your hub bolts, although I wouldn’t even think this is necessary.
The bigger concern I would have is the clutch hub is now slightly off balance, which would increase vibration and will slightly decrease the lifespan of your clutch bearing. I will say the clutch bearing was also designed with some factor of safety as well so it can probably handle the small amount of added vibration however, it will impact the overall lift of the bearing in the long run.

Sorry for the long winded answer but I wanted to try and give a better response than simply just “Yes” or “No”. If it were my bike, I would probably just file down any sharp edges and put it back in. If the vibrations were that noticeable, then I would consider replacing it (and purchase the right tools for the job!). Also, be sure to check for other cracks in the hub to be sure nothing will break off later. My buddy did the same thing you did because he jammed tire irons in his basket and the hub spun when he hit the nut with an impact and broke a piece of the hub off in his ’14 250SX. He put it back together and it’s totally fine so far, 2 months in.

Obviously it’s your call so do what you think is right!