but on this, and I believe I disused this before.

No, I don't think this was ever working, but I started to notice it recently, as I am performing full-length real time launches (small offset causes a small torque which, during long engine burn, becomes cumulative and very prominent). Not sure what you mean by "bad rows"...

bad rows in a linear system of equation is a row that make the soliton unstable.

basically a the system is linearizes and has the form

Y' = A * y + B * u

where A and B are positive semi finite matrix , you can determine the system stability be makin sure that the gienevalues of the matrix A are all positive an smallest the 1.0

when a system is unstable them matrix B is usually a diagonal matrix introduced to make sure that any rows with any potential larger the 1.0 engine value is made smaller that one.

but that is quiet technical, but is the job that people who design control system do all the time.

assuming the system is fine, what kind of control you have in the system? the way you test that is that you place you system in any steady stable trajectory and you apply some perturbation, if the system recover the it is stable and Seoul cope with any small misalignments.

if it does not recover the you nee to check if the system is unstable meaning is doe no have any equilibrium point, and is no is just a bad design. if is recovers the it mean you can add some control system. example of that are fling wing, and rockets, over steering race cars they are all unstable without a control system.

anyway can you make the repro, let us see what is wrong first.