Can plants yield two more molecules of ATP from glycolysis?
Plants produce ATP in the ‘light reaction’ of photosynthesis.
The purpose of the Calvin cycle (the ‘dark reactions’) is to produce glucose, for which it uses some of this ATP to provide the energy to make carbon–carbon bonds.
Glycolyis in plants functions to produce ATP from reserve carbohydrate etc. when ATP is not available from photosynthesis, or in tissues, that do not have sufficient ATP from photosynthesis.


So this question makes no physiological sense†, as it is based on a misunderstanding of the purposes of the differ metabolic reactions in plants. The answer is not that it cannot happen, but that it would not happen — the regulatory mechanisms that prevent futile cycling of pathways would come into operation.

† It is analogous to saying that the liver can perform gluconeogenesis, and so can produce glyceraldehyde 3-phosphate. So can the liver bypass this step...