I have attached a screenshot @Enivid to illustrate the condition.I'm not sure that there is a good way to do that. The default behavior should definitely be the current one - to limit the risk, the rounding of position size is always done down. The only way that I think this could be solved is by adding another panel control to the Script tab.
But how did you get 0.29 calculated by the indicator in the first place? Position Size Calculator indicator respects the volume step parameter just like PSC-Trader script.