Throughput accounting

Good Afternoon Sir
below is a question i have worked in the F5 text book. however i have a small query:

Question:
F Co makes and sells two products,A & B, each of which passes through the same automated production operations.The following estimated information is available for period 1;

Direct material A- $2
Direct material B- $40

Variable production overhead costs A – $28
Variable production overhead costs B – $4

Original estimates of production/sales of A & B are 120,000 units and 45,000 units respectively. The selling price per unit of A & B are $60 & $70 respectively.

Maximum demand for each product is 20% above the estimated sales levels.

Total fix production overheads cost is $1,470,000. This is absorbed by products A & B at an average rate per hour based on the estimated production levels.

one of the production operations has a maximum capacity of 3075 hours which has been identified as a bottleneck, limiting the overall estimated production/sales of product A & B. The bottleneck hours required per product unit for products A & B are 0.02 and 0.015 respectively.

Required:
There are several questions on this question to answer by calculating the answer through limiting factor analysis and throughtput however two question on throughtput use the same amount of Overhead expense and i couldnt understand why.

one of the question ask: If FCo choose to prioritize the manufacture of Product A, calculate the value (in$) of the maximun net profit using throughput analysis:

Answer in the tx:

Product A – 144,000 units x 58 throughtput return = 8,352,000
Product B – 13,000 units x 30 throughtput return = 390,000
Total ThroughtPut = 8,742,000

Less overhead costs:
Shown as variable in limiting factor analysis ((120,000x$28 + (45000x$4)) = (3,540,000)

Fixed= (1,470, 000)

Maximum net profit = 3,732,000

Query 1 : When they ask for mamimum net profit does it means the profit for both products since the question mentioned A, i calculate the profit for A alone :(. (or saying A was just an indication to start the mix wit A and not B, but the question was basically asking for overall profit?)

Query 2: regardless if its throughtput or limiting factor analysis if we are going to make the product that earn us the highest return, budget should no longer have any value right? in this scenario i did the entire calculation right with the product mix etc, however i dont understand why would would they text use the budgeted production volume to calculate the variable overhead cost base on our new mix? can please provide some clarity why.

the other question ask for the throughput on B and uses the same (3540000) added to fix cost to find the factory costs per bottleneck resource?