Hmm ... I see 2 other alternatives (there might be other alternatives using GTL or sgplot, etc, that I don't know about).
1 - Use proc boxplot (or other sas analytics procs) to generate a data set containing the values describing the boxplot, and then use annotate to actually draw the boxplot geometry onto an empty gplot set of axes. This would take a bit of work, but it *could* be done this way (I've done something similar in a special dashboard before).
2 - Use dev=activex to draw the SAS/GRAPH gplot bar chart, and then have your QA person view the graph in a browser, and hover their mouse over the boxes to see the actual box values. This is still a bit manual/interactive, but at least you get to see the actual/exact numeric values used in the boxplot (median, low, high, 25th percentile, 75th percentile). Below is some code:
%let name=plt036;
filename odsout '.';
GOPTIONS DEVICE=activex;
ODS LISTING CLOSE;
ODS HTML path=odsout body="&name..htm";
symbol1 interpol=BOX25 color=black width=1 bwidth=4 mode=include;
title "Activex boxplot: hover over boxes to see values";
proc gplot data=sashelp.cars;
plot msrp * type;
run;
quit;
ODS HTML CLOSE;
ODS LISTING;