| Hydrocarbon–oxygen systems | Long-established liquid-fuel rocket technology, with mature engineering and published flight experience. | Practical baseline for reliability, system complexity, storage and documented performance. |
| Liquid hydrogen–oxygen systems | Proven high-performance cryogenic propulsion technology. | Performance benchmarks must be weighed against specialised storage and handling infrastructure. |
| Established solid-propellant systems | Mature formulations and hardware developed for particular flight applications. | Different storage, handling and thrust-control characteristics; not directly interchangeable with a proposed liquid-material concept. |
| Ionic-liquid propulsion research | Peer-reviewed investigations establish that certain ionic liquids have propulsion-relevant properties. | Findings are compound-specific; they cannot automatically be extended to every imidazolium liquid. |
| Boron-containing fuel research | Published studies identify attractive theoretical energy content alongside major practical combustion constraints. | Potential energy content alone cannot establish useful delivered propulsion performance. |
| ItisScientific three-component concept | Research proposal combining imidazolium-based materials, ethanol and elemental boron. | No experimental performance comparison is yet established; feasibility, risk and rights must be evaluated first. |