I read that the Women's Enfranchisement Act (1930) extended the right to vote to all white women over the age of 21, regardless of land ownership or marital status.
On the other hand, non-landowning white men could not vote until the Franchise Laws Amendment Act (1931).
For a year, voting was more open to white women than white men. How was this perceived by society at large? Specifically, are their instances of poor white men taking issue with the fact that their wives could vote while they could not?
There was no general election during that period; elections were held in 1929 and then 1933. It also only applied in two of the four provinces; all white men in the Transvaal and the Orange Free State had held the franchise from the formation of the Union in 1910.
I can't find any sources that mention any controversy over the discrepancy. For example my go-to source on the development of the franchise under the union, Ian Loveland's By due process of law? passes over it in one sentence (but of course his focus is race rather than gender).
In Women and gender in southern Africa to 1945 (reproduced here), Cherryl Walker refers to it as an "anomalous situation" but doesn't suggest any particular controversy:
Through [the 1930 Act] adult suffrage was extended to white women in all four provinces - the anomalous situation thus created in the Cape, where the qualified franchise still applied to men, being rectified with regard to white men the following year when universal suffrage was granted to them as well (thereby further diluting the value of the African vote).