The antonyms for "more reckoning" can be various depending on the context in which the word is being used. Generally, when we use reckoning, it means a calculation or estimation of something. In this case, some antonyms for "more reckoning" could be less reckoning, no reckoning, or not reckoning at all.
However, if we are talking about a positive aspect of reckoning, such as understanding the importance or value of something, then the antonyms may be ignorance, disregard, or underestimation.
In other contexts, such as in literature or writing, the antonyms for "more reckoning" could be avoiding or neglecting to address a particular issue, or simply focusing on a different topic altogether.