We study boundary-selected burst phenomena induced by a finite inhomogeneous modulation region in a one-dimensional non-Hermitian dissipative crossstitch lattice. Compared with point defects, a finite modulated segment embedded in a uniform background is a more realistic form of spatial inhomogeneity and naturally generates two candidate effective interfaces. By simultaneously modulating the intracell coupling and local dissipation within the segment, we construct such an inhomogeneous region and map the model, via a local basis transformation, onto a non-Hermitian SSH chain with a finite parameter-mismatch region. Our dynamical analysis shows that under periodic boundary conditions the long-time dissipation peak does not emerge inside the modulated region, but is pinned to its boundary. The dominant burst is selected by the first interface encountered along the preferred nonreciprocal propagation direction. The burst intensity is further found to be governed not solely by the modulation strength η, but by the competition between effective-boundary trapping and local dissipation near the initial position. When the initial state is prepared inside the modulated region, increasing η enhances local dissipation near the initial position and suppresses the effective-left-boundary burst; when the initial state is prepared in the uniform background, the local dissipation near the initial position changes only weakly with η, while the effective-left-boundary burst exhibits an approximately inverse-Lorentzian-like dependence on ln η. For open boundary conditions, a representative dissipation profile shows that pronounced peaks appear at the effective left interface and at the physical left edge, whereas no comparable enhancement occurs inside the modulated region or at the opposite interface. This demonstrates that finite-region interfaces and physical open boundaries obey a unified boundary-selection mechanism. Our results clarify how nonreciprocal transport, interface effects, and dissipation compete in non-Hermitian lattices, and provide a theoretical basis for directional control of dissipation via regional modulation.