Catholic not sure if Jews must explicitly accept Jesus for salvation or not.
I don't think they said they weren't sure, they said it was an unfathomable Divine mystery.
I am sure Jews must accept Jesus explicitly unless he never hear about Jesus et all than it may under category of Rome 2.
Paul also says it is a mystery.
Romans 11: 26 and so all Israel will be saved. Even as it is written, "There will come out of Zion the Deliverer, and he will turn away ungodliness from Jacob. 27 This is my covenant to them, when I will take away their sins." 28 Concerning the Good News, they are enemies for your sake. But concerning the election, they are beloved for the fathers' sake. 29 For the gifts and the calling of God are irrevocable.
How does this happen, that all Israel is saved?
Please tell me in your own words how you believe all Israel will be saved.
Not matter if missionary effort to convert Jews
26 “ ‘Go to your people. Say to them,
“You will hear but never understand.
You will see but never know what you are seeing.”
27 These people’s hearts have become stubborn.
They can barely hear with their ears.
They have closed their eyes.
Otherwise they might see with their eyes.
They might hear with their ears.
They might understand with their hearts.
They might turn, and then I would heal them.’ (Isaiah 6:9,10)
28-29 “Here is what I want you to know. God has sent his salvation to the Gentiles. And they will listen!”
https://www.biblegateway.com/passage/?search=Acts+28&version=NIRV
See? Paul, who said he preaches first to the Jew and then to the Greek, now makes a final statement. He says the gospel is going to the gentiles.
In other places Catholics say that they want to evangelize everyone. So, it's just that there is no special mission to the Jews, which is exactly what Paul is saying here.
But any Jewish person, as well as any gentile, is welcome to walk into a Catholic Church anytime.