The SON sold the stock given to him be the parents.  The 1099-B goes to whomever sold the stock.  I hope the parents have the cost basis of the stock purchases from the parents.   He will need this to determine the taxable gain.

It doesn't do the calculations.   As you said, "type $300 in Line 10b".    ProSeries should do the calculations for line 10b, if there are figures in Schedule A for Cash Contributions, and standard deductions are used. This should be simple logic. Probably, their programmers are working on many other things now with the last minute legislation in December.

"Typing" $300 in Line 10b doesn't work.  Nothing typed onto the Form 1040 line 10b enters.  You can override the blank space in line 10b, BUT line 10c does not do the subtraction of the $300.. Let's face it, Intuit has not finished the programming for line 10b. This affects a lot of returns where the taxpayer(s) take a standard deduction.

$500 was already entered on 1040 Schedule A as Charitable Contributions,  Schedule A, line 11 shows the $500 contribution total.   Nothing appears in 1040, line 10b.   Should have shown $300.  Itemized deductions were less than the standard deduction.   So, it looks like 1040, line 10b is not working in ProSeries.

Users keep submitting comments that the Intuit Query function is extremely basic, and that more Query function would be helpful.  Intuit's Community Managers say they are "reviewing" these ideas.  Better queries will never happen for users, unless Intuit can find a way to make more money off the Query function.

"But my question here is, what makes you think the 1099-G is going to be mailed to the taxpayer whose identity was stolen, anyway?" In Illinois, there have been many thousands of fraudulent on-line applications for unemployment benefit.  The state is mailing follow-up notices to the original taxpayers at their state income tax filing addresses.  The taxpayers did not even know their identity had been stolen until they receive the follow-up notice.  So, yes, I expect they will receive 1099-G forms showing the unemployment benefits electronically paid the fraudsters.

The practitioner should refer to IRS Pub 501 Dependents, Standard Deduction, and Filing Information for 2020 return to determine if the young taxpayer is a dependent of the parent, or not. Always remember, a dependent is never a choice.  It is determined by the facts and circumstances applied to the IRS definition of a dependent.

3 months ago, the IRS was telling practitioners to fax in Form 7200 to get a quick refund, rather than putting the overpayment on Form 941 to be sent to the client. The IRS practitioner liaisons today do not even know that these fast Form 7200 refunds are not being processed. Since they are ignoring Form 7200, I am asking for full refunds on 3rd Quarter 941s being done at this time.

I posted the following in Intuit Community two days ago.  This is just one example of user based queries that we would like to see.  I could use such a new query function maybe a dozen times a year.   We should be more than just tax return preparors. "I would like to be able to identify clients who receive Unemployment Compensation in 2019 returns. Is there a way to search for this within ProSeries?" Earlier in the day, I had called Intuit Tech Support about specific queries.  The support person said that questions like this often come up.  However, Intuit's current Query function is VERY LIMITED.   I was told it goes back many years when computer data queries were more limited by data processing considerations.

The IRS has announced that they are now accepting eFiled 1040-X returns. Pro-Series had the following announcement yesterday, Aug 18: "We expect this functionality to be available in ProSeries around August 26.  ....  We will issue another product alert when this release is available."