Specific Emitter Identification (SEI) detects, characterizes, and identifies emitters by exploiting distinct, inherent, and unintentional features present in their transmitted signals. Since its introduction a significant amount of work has been conducted; however, most assume the emitters are passive and that their identifying signal features are immutable and difficult to mimic. Suggesting the emitters are reluctant and incapable of developing and implementing effective SEI countermeasures; however, Deep Learning (DL) has been shown capable of learning emitter-specific features directly from their raw in-phase and quadrature signal samples and Software-Defined Radios (SDRs) are capable of manipulating them. Based on these capabilities, it is fair to question the ease at which an emitter can effectively mimic the SEI features of another or manipulate its own to hinder or defeat SEI. This work considers SEI mimicry using three signal features mimicking countermeasures; “off-the-self” DL; two SDRs of different sizes, weights, power, and cost (SWaP-C); handcrafted and DL-based SEI processes, and a “coffee shop” deployment. Our results show “off-the-shelf” DL algorithms and SDR enables SEI mimicry; however, adversary success is hindered by: (i) the use of decoy emitter signals, (ii) integration of a denoising autoencoder, and (iii) SDR SWaP-C constraints.