%@ returns the incorrect trim bounding box.

[huxleyElateral]

When using GM that uses a subclass of {imageMagick : true} or { imageMagick: '7+'} with an image containing white space the incorrect trim bounding box is returned i.e.
0x0+250+300.

When using GM that uses a subclass of {imageMagick : true} or { imageMagick: '7+'} with an image not containing white space the incorrect trim bounding box is returned i.e.
0x0+250+300. // still looks off

When using GM that does not use the subclass with an image containing white space the incorrect trim bounding box is still returned while the format looks better i.e.
250x300+0+0. // while now the format looks better, this is not the trim bounding box, running imageMagick locally with the formatter of '%@' will return the correct trim box of i.e. 150x150+30+60

adding small examle of the problem

gm-trim-box.zip