Due to the recent developments in the field of full-duplex radios and cognitive radios, a new class of reactive jamming attacks has gained attention wherein an adversary transmits jamming energy over the victim's frequency band and also monitors various energy statistics in the network so as to detect countermeasures, thereby trapping the victim. Although cooperative mitigation strategies against such security threats exist, they are known to incur spectral-efficiency loss on the helper node, and are also not robust to variable latency-constraints on victim's messages. Identifying these research gaps in existing countermeasures against reactive jamming attacks, we propose a family of helper-friendly cooperative mitigation strategies that are applicable for a wide-range of latency-requirements on the victim's messages as well as practical radio hardware at the helper nodes. The proposed strategies are designed to facilitate reliable communication for the victim, without compromising the helper's spectral efficiency and also minimally disturbing the various energy statistics in the network. For theoretical guarantees on their efficacy, interesting optimization problems are formulated on the choice of the underlying parameters, followed by extensive mathematical analyses on their error-performance and covertness. Experimental results indicate that the proposed strategies should be preferred over the state-of-the-art methods when the helper node is unwilling to compromise on its error performance for assisting the victim.