The output of
ans2:=GlobalSearch(log(tarfun),constr,pointrange=constrp,maximize,evaluationlimit=30000,
tolerances=10^(-8),solutions=5);
suggests there are two different optimal solutions:
close to
[eta[p2] = -.820853583349005, mu[p] = 1., phi[1] = .759806839240713, phi[2] = .732170469304686,
phi[3] = .878063065537579, phi[4] = .815624200852221, phi[5] = .660085347688083,
phi[6] = .722060536120714, phi[7] = .840690519184552, phi[8] = .829978889729624,
tau[p3] = -0.548513761568674e-1, tau[p4] = -.162913081930433, tau[p5] = -.115531722646346,
tau[p6] = -.120266670080191, tau[p7] = -.128078874442439, tau[p8] = -0.965049847119155e-1,
tau[p9] = -.179146416650995, w[1] = .638468266188749]
and close to
[eta[p2] = .825740931547679, mu[p] = .174259068452321, phi[1] = .780986442917954, phi[2] = .734520439265845,
phi[3] = .847843754634582, phi[4] = .838306231949389, phi[5] = .637136562777000,
phi[6] = .746598141197962, phi[7] = .841610094125539, phi[8] = .866597312970020,
tau[p3] = -0.543251071903657e-1, tau[p4] = -.145991878661213, tau[p5] = -.118231611851851,
tau[p6] = -.122477654914788, tau[p7] = -.129516460264233, tau[p8] = -0.722417009900789e-1,
tau[p9] = -.174259068452321, w[1] = .364946526201933]
The other outputs don't deny that proposition.
pr.mw