Yes, the weapon you've described could theoretically be developed as a side product or a parallel research path during nuclear weapon development for several reasons:

1. Technological Similarities:

   • Material Science: Understanding materials under extreme conditions (like those used in nuclear weapons) could lead to innovations in creating highly reactive or explosive materials for non-nuclear applications.
   • Implosion Techniques: The development of implosion methods for nuclear weapons could naturally extend to designing systems where chemical explosives compress and initiate other materials.

2. Testing and Experimentation:

   • In the process of developing nuclear weapons, countries might explore various materials and configurations for their explosive and incendiary properties. Research into highly reactive materials like lithium, sodium, and magnesium might be part of such explorations, leading to the development of unique non-nuclear explosive devices.

3. Alternative Destructive Mechanisms:

   • The goal of nuclear weapon development is to maximize energy release. Scientists and engineers might experiment with alternative or supplementary mechanisms to achieve similar destructive effects without nuclear fission, leading to weapons that utilize extreme chemical reactions.

4. Tactical and Strategic Needs:

   • During the Cold War or in any scenario where nuclear weapon use is politically or strategically unfeasible, there might be interest in developing weapons that can offer some of the terror and destruction of nuclear bombs but without the political ramifications or radioactive fallout. This could lead to the creation of such a weapon as a deterrent or battlefield tool.

5. Crossover in Research:

   • The study of how materials behave under the extreme conditions of nuclear explosions (like heat, pressure, and rapid expansion) could inform the design of conventional explosives that mimic some of these effects.
   • The research into high explosives for nuclear weapon triggers (like TATB) could be adapted for use in different weapon configurations.

6. Psychological Warfare:

   • A weapon that mimics some aspects of a nuclear explosion might be developed to create fear or uncertainty on the battlefield, leveraging the psychological impact of nuclear weapons without the actual use of nuclear materials.

7. Material Utilization:

   • During nuclear weapon development, there might be excess or alternative materials that, while not suitable for nuclear weapons, could be utilized in other explosive or incendiary devices.

However, there are several caveats to consider:

• Development Intent:

  • If this weapon were indeed a side product, the intent behind its development would differ significantly from that of a nuclear weapon. It would be designed for its unique chemical and thermal effects rather than nuclear reactions.

• Ethical and Legal Considerations:

  • Developing weapons that incinerate or chemically alter human remains on such a scale still raises significant ethical and legal issues under international humanitarian law, similar to concerns with nuclear weapons.

• Technological Leap:

  • While the basic principle of using an explosive to compress and ignite another might be inspired by nuclear weapon design, the specific application of metal alloys for chemical destruction would require its own technological development, not necessarily directly derived from nuclear weapon research.

In summary, while the concept and some technologies could indeed be a byproduct or a related branch of nuclear weapon development, the specific weapon design you've described would represent a distinct application where the focus is on chemical and thermal destruction rather than nuclear energy release.