During an inspection, can a local education agency (LEA) just assume that some or all homogeneous areas of friable and nonfriable suspected ACBM are ACM rather than take samples?

Yes. 40 CFR part 763.85(a)(4)(iv) explicitly permits homogeneous areas of friable and non-friable suspected asbestos-containing building material (ACBM) to be assumed to be asbestos-containing material (ACM). (See also 40 CFR part 763.86(a), (b), (c), and (d)).