How to improve the smoothness of ContourPlot3D at the boundary

I want to ContourPlot3D[] a iso-surface. $3$ independent variable are α1, α2, Ψ, respectively. The codes are as follows (the equation is relatively complicated).

ContourPlot3D[-((π Cos[ 1/2 5 (ArcCos[(-1 + Sin[(π ψ)/360]^2 Tan[(π α1)/ 180]^2)/( 1 + Sin[(π ψ)/360]^2 Tan[(π α1)/ 180]^2)] - ArcCos[(-1 + Sin[(π ψ)/360]^2 Tan[(π α2)/ 180]^2)/( 1 + Sin[(π ψ)/360]^2 Tan[(π α2)/ 180]^2)])] Cot[(π ψ)/360] Csc[(π ψ)/ 360]^2)/(360 Sqrt[ Csc[(π ψ)/360]^2 + Tan[(π α1)/180]^2] (-Tan[(π α1)/180] + Tan[(π α2)/180]))) + (π Cot[(π ψ)/ 360] Csc[(π ψ)/360]^2)/( 360 (-Tan[(π α1)/180] + Tan[(π α2)/180]) Sqrt[ Csc[(π ψ)/360]^2 + Tan[(π α2)/180]^2]) - 1/(2 (-Tan[(π α1)/180] + Tan[(π α2)/180])) 5 Sin[1/ 2 5 (ArcCos[(-1 + Sin[(π ψ)/360]^2 Tan[(π α1)/180]^2)/( 1 + Sin[(π ψ)/360]^2 Tan[(π α1)/ 180]^2)] - ArcCos[(-1 + Sin[(π ψ)/360]^2 Tan[(π α2)/180]^2)/( 1 + Sin[(π ψ)/360]^2 Tan[(π α2)/ 180]^2)])] Sqrt[ Csc[(π ψ)/360]^2 + Tan[(π α1)/ 180]^2] (-((-((π Cos[(π ψ)/360] Sin[(π ψ)/ 360] Tan[(π α1)/ 180]^2 (-1 + Sin[(π ψ)/360]^2 Tan[(π α1)/ 180]^2))/(180 (1 + Sin[(π ψ)/360]^2 Tan[(π α1)/ 180]^2)^2)) + (π Cos[(π ψ)/ 360] Sin[(π ψ)/360] Tan[(π α1)/ 180]^2)/( 180 (1 + Sin[(π ψ)/360]^2 Tan[(π α1)/ 180]^2)))/(Sqrt[ 1 - (-1 + Sin[(π ψ)/360]^2 Tan[(π α1)/ 180]^2)^2/(1 + Sin[(π ψ)/360]^2 Tan[(π α1)/ 180]^2)^2])) + (-((π Cos[(π ψ)/ 360] Sin[(π ψ)/360] Tan[(π α2)/ 180]^2 (-1 + Sin[(π ψ)/360]^2 Tan[(π α2)/ 180]^2))/( 180 (1 + Sin[(π ψ)/360]^2 Tan[(π α2)/ 180]^2)^2)) + (π Cos[(π ψ)/ 360] Sin[(π ψ)/360] Tan[(π α2)/180]^2)/ ( 180 (1 + Sin[(π ψ)/360]^2 Tan[(π α2)/ 180]^2)))/(Sqrt[ 1 - (-1 + Sin[(π ψ)/360]^2 Tan[(π α2)/ 180]^2)^2/(1 + Sin[(π ψ)/360]^2 Tan[(π α2)/ 180]^2)^2])) == 0, {α1, 0 + 0.1, 90 - 0.1}, {α2, 0 + 0.1, 90 - 0.1}, {ψ, 0.2, 180 - 0.2}, RegionFunction -> Function[{α1, α2, ψ}, α1 < α2], Mesh -> None, ContourStyle -> Directive[Opacity[0.8], Orange], FaceGrids -> {{-1, 0, 0}, {0, 1, 0}, {0, 0, -1}}, PlotTheme -> "Scientific", PerformanceGoal -> "Quality"] 

As we can see from the following picture, at boundary α1 = α2, the surface is far from smooth, (maybe because of infinitesimal in the denominator), I tried to use options MaxReursion and PlotPoints in ContourPlot3D[], but result didn't improves..., So how can I improve this?