Answer: You are right, there is language on this in the law. It is in the section on quality of subgrant applications:
“(3) QUALITY- In determining the quality of applications under paragraph (1), the State educational agency shall consider the following: …
(G) The extent to which the local educational agency will use the subgrant to leverage resources, including by maximizing nonsubgrant funding for the position of the liaison described in section 722(g)(1)(J)(ii) and the provision of transportation.”
The citation for that language is 42 USC 11433(c)(3)(G).