Sorry for my misunderstanding @Fiona_Baines, I think I better understand now your use case.
By using this setup for the DOE (and using only main effects in the model) :
And by specifying optimality criterion as Alias-Optimal, increasing design search time and number of random starts (to converge towards the design you want), I am able to have the design you expect :
Here is the script is you want to reproduce it :
DOE(
Custom Design,
{Add Response( Maximize, "Y", ., ., . ),
Add Factor(
Categorical,
{"S1", "S2", "S3", "S4", "S5", "S6", "S7", "S8"},
"Treatment",
0
), Add Factor( Categorical, {"1", "2", "3", "4"}, "Row", 0 ),
Add Factor( Categorical, {"A", "B", "C", "D"}, "Col", 0 ),
Add Factor( Categorical, {"1", "2", "3", "4"}, "Blocking", 0 ),
Set Random Seed( 1635750691 ), Number of Starts( 77 ), Add Term( {1, 0} ),
Add Term( {1, 1} ), Add Term( {2, 1} ), Add Term( {3, 1} ), Add Term( {4, 1} ),
Add Alias Term( {1, 1}, {2, 1} ), Add Alias Term( {1, 1}, {3, 1} ),
Add Alias Term( {1, 1}, {4, 1} ), Add Alias Term( {2, 1}, {3, 1} ),
Add Alias Term( {2, 1}, {4, 1} ), Add Alias Term( {3, 1}, {4, 1} ),
Set Sample Size( 64 ), Optimality Criterion( "Make Alias Optimal Design" ),
Simulate Responses( 0 ), Save X Matrix( 0 ), Make Design,
Set Run Order( Randomize within Blocks ), Make Table}
)
And attached the datatable with graph script.
There might be a more straightforward and easier way to do this design, but this option can still be helpful.
This design should better fit with your expectations
Victor GUILLER
"It is not unusual for a well-designed experiment to analyze itself" (Box, Hunter and Hunter)