Is that 5 stops? Linear mult by 5? Or something else? “Exposure raised up to 5” is ambiguous.
Part of what you are seeing is the difference between the overexposure handling of the picture rendering in the ACES RRT/ODT combo, and that in spi-anim. There is no one “right” way to map scene to display referred. If for example you use an OCIOColourSpace node to transform from ACEScg to LogC Wide Gamut with increased exposure, you will see a different result again. The ARRI LUT handles the blue ball in an arguable more aesthetically pleasing way, but creates unpleasant artefacts on the red one:
Both the above images have linear mult of 5 applied in ACEScg.
But also, I believe spi-anim expects sRGB primaries, and your image has ACEScg primaries (or at least the ACES 1.0.3 config is treating it that way). If spi-anim is then interpreting those same code values as having sRGB primaries, they will appear to be very desaturated compared to the colours they represent in ACEScg. If you apply an ACEScg to sRGB matrix to the image first (which arguably is the correct thing to do) the result of raising exposure in spi-anim is far less visually pleasing, going very quickly into clippy, saturated colours, with no visible specular.
For reference, the ACEScg to sRGB matrix, using CAT02 is:
1.70507964 -0.62423346 -0.08084618
-0.12970053 1.13846855 -0.00876802
-0.02416634 -0.12461416 1.14878050
Multiply that matrix by [0.097, 0.754, 5.473] and you get [-0.7477501, 0.797837, 6.190972]. So your CG render has produced a colour which is way outside the sRGB gamut. So it’s up for debate what the “best” way to map that to an sRGB/Rec.709 display is even before you increase the exposure.