Although there are considerations to include IPFIX in PRTG, I'm afraid there are no near-future plans to this extent. In this sense, we would be hard-pressed to let you know when such a functionality will be available.
Seeing as we have no actual experience with these tools (we're guessing you mean "pmacct"), I'm afraid we cannot really say which one would be the better option - or if the converted data will be readily usable with PRTG. Perhaps someone else has tried or, if you try yourself, you could let us know which is easier / more compatible to use with PRTG.
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