WRT "high performance", it's perfectly fine to write, "This armor has high performance." It's not actually incorrect, as far as I know, to write, "high performance ballistic protection", but it's unnecessarily ambiguous: the parsing that is intended is ((high performance) (ballistic protection)), but it parses equally well as (high (performance (ballistic protection))), which doesn't make sense, so we know it isn't the intended meaning. The authors use the less-ambiguous punctuation two sentences later. "Lightweight" achieved wordhood decades ago, maybe more than a century, and therefore has no need for the apologetic hyphen.

The issue with "its" is that it's singular, but its antecedent (or postcedent, if you will) is "composite foams", which is plural, and used with the plural form of "have". So "its" here violates pronoun-antecedent agreement.

The problem with violating grammatical rules (whether they're the rules of academic English or of AAVE) is not that it's morally wrong; it's that it makes you hard to understand. In fact there are people who would have understood and made use of their research who will not do so. If the errors were more serious, the number of people thus excluded would be larger, but it's still nonzero. Some of those people will simply remain ignorant of the results these researchers attempted to publish; others will get them from another source, perhaps an experiment done by someone who was ignorant of the results, assuming that the results are correct. Perhaps metal-foam composites research will lag behind where it would have been with a more coherent paper, and alternative forms of armor (aerogels, say) will become dominant instead, and the researchers and their research will languish in obscurity.

Another part of the problem is that the sloppy abstract signals to readers that the researchers had very low standards for the paper—perhaps if I attempt to reproduce their results, I will discover that they misstated the composition of their strike plate, omitted crucial details like the density of the spheres or which stainless steel they used for the matrix and how they sintered it, or even incorrectly measured the deformation of the backplate.

If you're writing formal papers in languages that aren't native to you, you should find a native speaker to write or at least proofread your abstract, if not the entire paper. Some people do this professionally at a cost substantially lower than the cost of fabricating a stainless-steel foam, so even if you're living in Bhutan, you can contract a professional writer. But the authors of this paper are at NCSU, which has 34000 students, over 29000 from the US, so presumably they have at least 25000 functionally-literate native English speakers in their very own university, most of whom would be willing to work for well below market rate and many of whom are actually interested in learning to Do Science.

But they didn't care about communicating their results.