I know you well enough to figure there must be something favorable about being assigned or you wouldn't have asked the question. lol Let's say I'm short the 50 put and the underlying is at 40. I'm either down 10 on long stock or I'm down 10 on a short put. So what's the advantage of being assigned?
Since we're at parity, I guess we must be at, or close to, expiration. If I let it ride, I'm going to be assigned anyway, which means I lose 10 points minus full premium. I would also have to have a ton of money in my account to cover tzzzzzzzzz-z-he long stock position. To me, that's a negative, unless I close the stock position immediately upon assignment, which I would.
If I buy back my short put, I would not only lose 10 points, but the premium collected would be reduced by the amount of the buy-back price. So in that scenario, I'd say assignment would be preferable.
You've thrown in an embedded call which just muddied the waters. And I don't know much of anything about embedded calls.
As it pertains to risk of loss, I would say the two are equal. But, again, knowing you, that embedded call must play a role in here somewhere.

With the short put, your gain is limited to the premium collected. With the long stock/embedded call, your upside could be limited to the call's strike.
So the overall risk (risk of loss/risk of missing potential gains) would probably be predicated on the long stock's entry price -- which I believe would have to be the same as the short put's strike for them to be at parity -- in conjunction with the embedded call's strike. So, for instance, if you brought in $500 premium on the short put, and the embedded call's strike was 5 points above the long stocks entry price, that would seem to be about even on the overall risk. But if the call's strike was over 5 points away, it would seem the overall risk would be less with the long stock.
I believe a long call and a short put, both ATM, same expiration. Not sure how that factors in to all this, but I'm sure you will tell me.
Okay, I probably butchered this, but as
@zdreg says, I'm just a first grader. lol