Correct placement of "not" next to "to" disambiguating a sentence

Question

I asked a question on another site and got corrected by someone. Them being NSE and me not, I appreciated the improvement except in one regard - placement of the negation. So I asked about it and as it turns out, they wasn't certain neither and we decided to ask here.

I'd also prefer to not use a method valid in an older version of PS, although working, if there's a more convenient approach in a later one.

I've been taught that it's incorrect to place not after the infinite marker to, so the original wording was hence like this.

I'm also concerned not to use a method valid in an older version of PS, although working, if there's a more convenient approach in a later one.

Partially, we're not entirely certain which is correct. Partially, they indicated that the construction might be ambiguous and difficult to interpret, even if it'd be grammatically correct.

1. Which formulation is correct?
2. Is the sentence ambiguous?

I believe this answer covers the matter of grammatical correctness and colloquial frequency. Although, it doesn't address the issue of ambiguity.

The indented meaning is intentionally left at the very end to avoid unconsciously influencing the reader. The point was that I prefer to use modern approach. It's possible that the same effect may be reached using different command patterns (one older - widely spread, and one newer - not well known yet but improved in terms of syntax, features etc.). Me being less experienced in the area, can't reliably decide whether it's the case. So, while inclined to using newer methodology, I raise no demand on the modernity, still wishing to mention the preference.

Answer 1

As pointed out in the comments, the original word that felt out of place was "concerned." I think it could still be used with a slight adjustment to place emphasis on "concerned" instead of "use." The phrasing of "although working" was also noted to be a bit ambiguous. It can be left off since it's not really critical to the preference expressed in the sentence.

If I were to rephrase the original again, I would go with this:

I'm also not concerned about using a method valid in older versions of PowerShell if there's a more convenient approach in a later one.

All that being said, the concept you're describing has a term for it: backward compatibility. While gratuitous use of jargon can sometimes make things difficult to read, this is a case where I feel it improves readability.

This is what I would suggest using instead:

Backward compatibility is unimportant if a modern PowerShell feature would allow for a more convenient approach.

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As for the question of "to not use" versus "not to use" the weight is heavily in favor of "not to use" at about 94% of occurrences according to the Corpus of Contemporary American English.

The linked answer from user Colin Fine made a couple of excellent points included here for reference:

The normal form of a negative infinitive is "not to X", in all contexts.

The form "to not X" is grammatical (notwithstanding the generations of people who have moaned about "splitting the infinitive"), but unusual, and would only be used in order to convey a special meaning.