effect.clm

I'm having a problem using the xlevels option with effect (or Effect) with
objects of class clm, which seems to have no impact on the output (whereas
it does for models of class polr).  Can anyone suggest how to fix this?

Thanks,
David

Here's an example:

mod.wvs <- MASS::polr(poverty ~ gender + religion + degree +
country*poly(age,3), data=WVS)

 Effect('age', mod.wvs, xlevels = list(age = 1:10))

Re-fitting to get Hessian

age effect (probability) for Too Little
age
        1         2         3         4         5         6         7
  8         9        10
0.8403661 0.8270171 0.8133710 0.7995001 0.7854780 0.7713778 0.7572714
0.7432277 0.7293120 0.7155850

age effect (probability) for About Right
age
        1         2         3         4         5         6         7
  8         9        10
0.1295679 0.1399772 0.1505377 0.1611853 0.1718564 0.1824888 0.1930231
0.2034039 0.2135803 0.2235068

age effect (probability) for Too Much
age
         1          2          3          4          5          6
 7          8          9         10
0.03006598 0.03300572 0.03609134 0.03931456 0.04266563 0.04613341
0.04970548 0.05336837 0.05710766 0.06090822

But with clm:

+                 data=WVS)