Hy Graechan...first i want you know that this as most of your logo script is included in GIMP-PhotoComix_Lab-2.8.2 (in both 32 and 64bit versions )
Anyway i was just using it now and i have problems with Keep layers option :
keep layers doesn't keep any of the layers i want to keep !
I see a lot of interesting layers flashing away and immediately merged,
as example one that looks as polished silver...cool but disappear in a flash would be no possible just replace (if Keep Layers is chosen) inside your script "merge layers" with "new layers from visible" so all the layers are really preserved ?
As example i would like add a blur + sharpen (1.5 gaussian blur + unsharpmask2) sequence on the metal but the BG already merged somehow disturb
But more i want see better and maybe somehow use that polished silver layer appears and vanish in a flash
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a bit OT ,did you experimented combination of blur/sharpen ? i found often very reward
A very moderate blur (below 1.5 px) followed by a moderate dark halo sharpening (as in gmic/enhance/sharpen/Unsharp, if lowering the + value to no much more then 0 ) often make the details pop out, more sharp but more sharp in a quite smooth way