A lot of these problems come from NOT sticking to the Plan/Source Material...
Prometheus Evolved from Jon Spaights Alien Engineers in this draft Fifield was more Xenomorph looking well a Hybrid and had ACID BLOOD...
In Prometheus the Hammerpedes had ACID Blood, the Trillobite is inconclusive, however the Full Scenes show us the Engineer had no Face Burn until after the Trillobite fight, if you watch the Full Scene or even Face Burn one, we can see for a few shots the Face is Burnt then not, then Burnt...
To me it looks like TWO Trilobite Scenes was shot, one where the Engineer at the end suffered a Acid Burn, then they decided to re-do the Engineer vs Shaw Scene and while in make up, no doubt got Ian Whyte to do another Trillobite Scene... The Final Scene we see in both Theatrical and deleted Scene appears to be a mash up of both potentially shot Trillobite vs Engineer Scene.
So its looks more likely that the Trilobite was intended to have ACID BLOOD
The Reason Because what was contained in the Urns is Genetically related to the Xenomorph/Deacon in the Mural, this appeared to be the Original idea...
Alien Covenant has muddied the waters because they never took much notice on previous source material.
Does the Neomorph have ACID Blood? Who knows i think this is one of those inconclusive things, so we cant say either way.