Clause. 1. Can I also apply for a tax refund for the additional deduction? No, you can't. The additional deduction is like a consumption voucher, you have 1 million inputs, you can deduct 100,000 more, and this 100,000 is given to you when you are a consumer. But you say that I don't spend, can I exchange it for cash directly? No.
Note that the additional deduction will not form an input tax, and the input is still 1 million, but you will be deducted by 100,000 more when deducting. Since the input tax is not formed, of course, it cannot apply for a tax refund.
Clause. 2. I have applied for the part of the tax refund, should the additional deduction amount that has been accrued be reduced? No, you don't. The retained tax refund is to refund the retained input tax when the output is insufficient, which is essentially equivalent to deducting the input in advance, and the premise that they can be deducted is that they meet the deduction regulations, so it does not belong to the input tax that cannot be deducted from the output tax according to the current regulations, so it can still be added and deducted. Then the additional deduction can be left there. In other words, although the voucher cannot be withdrawn, it can be kept for a later period. 
Third, Announcement No. 39 states that if the sum of the sales of the four types of services accounts for more than 50% of the total sales of taxpayers, then taxpayers can enjoy the policy of additional regression. So does it mean that the income formed by operating other businesses can also be expedited and deducted? Or is it only the part of the production and living services that can be used? Once the proportion of sales in line with the policy provisions is met, the taxpayer as a whole is used as the basis for calculating the additional deduction, and no longer distinguishes the business, except for export goods and services and cross-border taxable behaviors.
Therefore, the additional deduction, the more inputs, the more deductions. The service industry is inherently lacking in inputs, while the processing and manufacturing industries are different, with a lot of inputs. Therefore, for some enterprises that have both production and living services and processing and manufacturing industries, if the arrangements are appropriate, they may enjoy more preferential treatment.