I need to correct my careless statement "WileyPLUS does not use a CAS".
Some problems in WileyPLUS mention they are graded by Maple (probably a subset of MapleTA). My testing showed that most of those problems would handle simple alternative forms, e.g., shift a sine to get a cosine, replace an arccos computation with an equivalent arctan expression.
On the other hand, intelligent use is a bit spotty. E.g., a problem involving exponential growth with correct answer of the form 3720 * (0.7^x) or 3720 * (0.7)^x systematically rejected 3720 * (.7^x) or 3720 * (.7)^x [i.e, leading zero was required for this problem, 0.7 instead of .7, but no message to students identified the form which the system would require for an answer to be scored as correct].