Oxy-fuel combustion in the Allam cycle of supercritical-CO₂ power plants must be highly diluted with recirculated CO₂, because the temperature rise within the combustor is ~400 °C only. Highly diluted oxy-fuel flames have been proven in the literature to be susceptible to early blowout. Hydrogen enrichment is a viable solution to deter blowout and enhance combustor turndown, owing to the eminent combustion characteristics of hydrogen (H₂). The author focused on the micromixer burner technology in gas turbines for its established superior flame stability. Two techniques were examined for introducing enrichment H₂ in an oxy-methane micromixer-based model gasturbine combustor: fully premixed with the oxy-reactants (i.e., CH₄/H₂/O₂/CO₂) and non-premixed/stratified (H₂−CH₄/O₂/CO₂). Since the onset of blowout in micromixer flame was observed to occur consistently at its circumference, the second (stratified) technique introduced H₂ in non-premixed fashion from peripheral jets surrounding the premixed CH₄/O₂/CO₂ core flame, with the aim to enhance combustor turndown by benefiting from inducing stratification. This approach thus attempted to use hydrogen to stabilize the peripheral region of the oxy-methane flame where blowout typically starts. It was found, however, that the blowout limit of fully-premixed (CH₄/H₂/O₂/CO₂) flame did not improve by stratification (H₂−CH₄/O₂/CO₂); it actually deteriorated slightly. The stability and CO emissions of the stratified flame as well as the interaction of H₂ jets with core CH₄/O₂/CO₂ flame in this technique were thus analyzed in detail, in order to explain this unexpected behavior and provide recommendations for how hydrogen enrichment should be introduced in oxy-fuel micromixer combustors.