We initiate the study of infinite-distance limits on (complex) multi-dimensional conformal manifolds of 4d SCFTs and their bulk interpretation as tensionless-string limits in AdS/CFT. In particular, we focus on 4d \( \mathcal{N} \) = 2 SU quiver gauge theories with hypermultiplets in the bifundamental and fundamental representations. In the overall-free limit, we compute the large-N Hagedorn temperature TH, which governs the stringy exponential growth of the density of states at high energies. We argue that this quantity determines the type of stringy ultraviolet completion in the bulk: it captures the type of string theory in which the bulk physics is embedded while remaining insensitive to detailed geometric data. For linear quivers, we find that TH depends only on the quiver length, which is tied to the number of NS5-branes in the underlying brane construction and, in turn, to the string theory in which the bulk is embedded. For holographic quivers, where we impose that the two central charges a and c coincide in the large-N limit, we show that TH coincides with that of \( \mathcal{N} \) = 4 SYM, which befits the 10d Type IIB description of their gravitational duals. We also analyze the exponential rate α, which controls how the leading tower of higher-spin currents becomes conserved in these limits, as suggested by the CFT Distance Conjecture. In the large-N regime, we derive sharp bounds on the minimal rate, \( 1/\sqrt{2} \) ≤ αmin ≤ \( \sqrt{2/3} \) , attained in the overall-free limit. Moreover, we prove that the universal lower bound α ≥ \( 1/\sqrt{2} \) holds, including at finite N. Finally, we go beyond the overall-free ray by characterizing the convex hull of the \( \overrightarrow{\alpha} \) -vectors that encode the exponential rate of the higher-spin towers along any (partial) weak-coupling limit.
