Well, 1st issue is that the syntax is wrong, the line should read.
Code:
linkage[table].field[cCstS4Expr].text &= " & abCategory.FtrAAShots"
Second issue is with timing, which I figured out by playing with it.
For my files and testing, I made my "runeguard" and arcane archer both have Quaternary abilities.
My intial script changes didn't work so I dug around and looked at the timing report. It seems that LoneWolf runs a script at Final/9999999 that initializes cCstS4Expr's text field. So, that means you can't play with the field until right after that.
So I took the line I suggested out and put it in a second script that runs immediately after LoneWolf's (at timing Final/10000000)
Example 2nd script:
Code:
doneif (tagis[Helper.Disable] <> 0)
linkage[table].field[cCstS4Expr].text &= " & abCategory.FtrAAShots"
This worked, now my arcane archer doesn't see anything but arcane shots for the quaternary ability. I did the same to my runeguard and now it can't see the arcane shots and only the runes.