From the responses I've gotten, no, there is no config option similar to maintain_limit_tol_nominal for asymmetric plus-minus dimensions.
The most-mentioned workaround is to set the Dimension Boundaries (Edit>Setup>Dim Bound in Wildfire, Analysis>Tolerance Analysis>Dimension Boundaries in Creo), selecting dimensions to use the upper, lower, middle, or nominal value to drive their features. This has to be done for each asymmetric plus-minus dimension.
Another solution is to just make each dimension nominally at the middle of the range, and make the tolerance symmetrical. This might be the easiest thing to do if company standards don't get in the way.
Alternatively, you can create a toolkit application to do this. I am told that the relevant TK API is ProDimensionBoundGet/Set.