These semileptonic observables described above offer an alternative test to the enhancement in $R_{D^{(\ast)}}$, without any assumption regarding the underlying NP structure. Model independent tests can also be obtained by using purely leptonic observables. As already anticipated in Sec. \[sec:eft\], the interactions responsibles for the anomalies in $R_{D^{(\ast)}}$ must respect $SU(2)_L \times U(1)_Y$ gauge invariance. Writing the operators as in Eq.  at a scale $\mu \gg \mathcal{O}(v_{\mathrm{EW}})$ opens up the possibility to study the impact of electroweak corrections within an effective field theory context. It has been shown in Ref. [@Feruglio:2016gvd; @Feruglio:2017rjo; @Cornella:2018tfd] that the operators generating the (current)$\times$(current) contributions to $R_{D^{(\ast)}}$ also induce sizable corrections to the $Z$-pole observables and to LFU tests in $\tau$-decays. On the other hand, the operators generating (pseudo)scalar and tensor contributions have the peculiarity of inducing chirality-enhanced contributions to $\mathcal{B}(h\to \tau\tau)$ and to the $\tau$-lepton anomalous magnetic moment, respectively, without inducing any sizable modification to the $Z$-pole observables and LFU tests in $\tau$-decays [@Feruglio:2018fxo]. The ongoing experimental effort at Belle-II and LHC will offer the opportunity to check for an additional enhancement in these observables. Finally, model-dependent predictions can also be obtained once a specific scenario is chosen. These include the signals at the 