Are you maybe looking for this: https://inkscape.org/~Klowner/%E2%98%85apply-transforms ? Another option is to ungroup and then regroup, with coordinate saving set to absolute in Edit > Preferences > Input/Output > SVG output.
Nope, SVG output setting absolute/relative is related only to paths and has nothing to do with transformations on group or objects in group.
Apply transform is nice idea, but still is not reliable at 100%. It just breaks more complicated drawings. I will report this to author in later time, now i am strict at some deadline.
Group / regroup is some solution but is inconvenient to do this manually - it is not one group. When group is exploded in inkscape then transforms are moved to nested groups or objects. Exploding nested groups in inkscape quite often making the transforms to return on parent group. So good extension like deep regroup is needed. For one drawing this inconvenience can be overlooked, but with many SVG ...
I am unfortunate to this point my work will be ported to external software which is using similar syntax to SVG specification but with some exceptions - transforms like matrix doesn't exists at all and translate is using in other way. Scale and rotate have the same function. But rotate is not using anymore in modern softs replaced by shorter matrix transform. Inkscape still using rotate but only when rotate is the only transform, otherwise matrix makes its enter. I really actually stand on my head only to make drawings compatible.
But my previous question has no sense - for illustrator CS6 it is better when the main group has all transforms. Illustrator is weird a little - it only use matrices and only when there is no possibility to flat transforms, but if other program created many transforms like inkscape like to do this, illustrator just leave them be - it even doesn't alter them applying own transforms directly on object and fitting all modification to be corelated with existed transforms.
EDIT: further tests showed that even with combination inkscape/illustrator CS6 i still can't get rid of some transforms.
Well, i will somehow fit my works to the limitations but it is really tiring ...