From the Southwest site
Table values reflect XHHW-2 conductors. +Allowable Ampacities:Allowable ampacities shown are for general use as specified by the National Electrical Code, 2011 Edition, Section 310.15.
60? C - When terminated to equipment for circuits rated 100 amperes or less or marked for 14 through 1 AWG conductors. See NEC Article 338.10(B)(4). 100A or less ? disagree
75? C - When terminated to equipment for circuits rated over 100 amperes or marked for conductors larger than 1 AWG. May not apply, see NEC Article Agree
338.10(B)(4).
90? C - Wet or dry locations. For ampacity derating purposes. Agree
Dwelling - For units, conductors shall be permitted at listed ampacities as 120/240-volt, 3-wire, single-phase services and feeders per NEC Article 310.15. Only in certain circumstances
310.15(A)(2) Exception310.15(A)(2) Exception is not mentioned -- Dennis do they have a written document to support your conversations?