The ASE results in larger enhancements for the DQ transition, while the SE appears more efficient than the ASE for the ZQ transition due to the lower microwave power. This observation brings to focus several experimental aspects of the ASE. Given a fixed pulse length, one can increase the sweep width to bring more electron spins across the matching condition. However, since this increases the sweep rate 𝜔̇, the DNP transfer ratio decreases (see Eqs. ( ) and ( ) and Fig. in Ref. ). This decrease of the DNP transfer ratio can be compensated by increasing ω $& to keep Q large. At sufficiently high 𝜔 $& the broader sweep be applied to cover additional electron spins, eventually transitioning to SSE. In the other extreme, where the microwave 𝜔 $& is lower, then the SE without chirping can be more efficient than ASE with chirping, which we observe for the ZQ transition. The optimization of the sweep width for the sample at 70 K is shown in Fig. . The first point is without chirping and corresponds to the SE, while the last point uses a chirp width of ~200 MHz and corresponds to the SSE. Additionally, the optimum repetition delay was determined to be 1.2 ms, which depends on the pulse sequence, the 𝑇 $/ , and the DNP transfer ratio.