Γ(x) & erf(x) have already been identified as requiring the integrand be vectorized.
The X^Y is even worst as it is not supported by the integrator.
The Smath X^Y is incompatible with the intent of this CAS software

Ref: Smath 6179 ... RemToUpgrade

Jean

Bug Numerical X^Y.sm (8 KiB) downloaded 61 time(s).

... X^Y is short of numerical viability, as exemplified.

Bug Numerical X^Y.sm (15 KiB) downloaded 62 time(s).