I guess it depends what you mean by "acceptable".
I would comment on it as poor style, because style guides are pretty much universal in saying that it is better to speak in positives:
12. Put statements in positive form
Make deﬁnite assertions. Avoid tame, colorless, hesitating, non-committal language.
5. Express Statements in Positive Form
The positive form of a statement is generally more concise and straightforward than the negative:
no: Don't write in the negative.
yes: Write in the affirmative.
no: Disengagement of the gears is not possible without locking mechanism release.
yes: To disengage the gears, you must first release the locking mechanism.
This justification for this advice is that positives are easier to process than negatives. In more infrequently, the 'more' suggests an increase, then the 'infrequently' reverses that by suggesting a decrease in 'more of less' sort of way, which is (allegedly) more difficult to understand than less frequently.