Thin film lithium niobate (TFLN) photonic integrated circuits offer several improvements over other platforms in terms of material loss, energy efficiency, and operational bandwidth, making them promising enablers for high data rate optical communication. We review our recent demonstration of quadrature phase shift keying in an ultrasmall TFLN photonic crystal-based IQ modulator. Our modulator features a footprint of 40 μm × 200 μm along with quality factors approaching 10^5 providing it with a V_π = 1.16 V [H. Larocque et al. CLEO 2023, paper STh1R.3; H. Larocque et al. arXiv:2312.16746]. We discuss an extension to and optimization of quadrature amplitude modulation encoding schemes tailored to the device’s voltage response, including the use of a deep neural network for streamlining bit error rate minimization.