Hi,
This question is primarily directed to those who have already attempted the CFA level 1 exam or at least have challenged some mock exams. My question is related to the complicated formula of the variance of the prediction error, that allows us to estimate the standard error of the forecast. The standard error of the forecast is used to obtain confidence intervals for predicted variables. (I believe that it is time-consuming and quite probable that one may make a mistake omitting a bracket in the calculator at some point) 
The LOS states LOS 7.g: Calculate and interpret the predicted value for the dependent variable, and a prediction interval for it, given an estimated linear regression model and a value for the independent variable.
I have been told that it is unlikely that candidates would be required to compute the standard error of the forecast themselves. Nevertheless, one of the steps, to achieve the goal of the above-mentioned LOS, is to compute it. Obviously, the safest way would be to learn and I will probably do it either way but was just wondering if this is something essential and should pay special attention to it. Any suggestions? Thanks in advance.
EDIT: Furthermore, at least one of the practical questions in the CFA curriculum for 2022 expects us to calculate the SEF.
source: problem 33, (p. 487)