  We introduce unique class of cyclic quantum thermal machines (QTMs) which can
maximize their performance at the finite value of cycle duration $\tau$ where
they are most irreversible. These QTMs are based on single-stroke thermodynamic
cycles realized by the non-equilibrium steady state (NESS) of the so-called
Periodically Refreshed Baths (PReB) process. We find that such QTMs can
interpolate between standard collisional QTMs, which consider repeated
interactions with single-site environments, and autonomous QTMs operated by
simultaneous coupling to multiple macroscopic baths. We discuss the physical
realization of such processes and show that their implementation requires a
finite number of copies of the baths. Interestingly, maximizing performance by
operating in the most irreversible point as a function of $\tau$ comes at the
cost of increasing the complexity of realizing such a regime, the latter
quantified by the increase in the number of copies of baths required. We
demonstrate this physics considering a simple example. We also introduce an
elegant description of the PReB process for Gaussian systems in terms of a
discrete-time Lyapunov equation. Further, our analysis also reveals interesting
connections with Zeno and anti-Zeno effects.
