... not sure how much time CNCdrive want to expend on the CAM side of things (is it a core feature, or just an aide?)
Some of this could be done via a new screenset for plasma, just renaming some of the existing labels or removing them and setting cut per pass = to the start depth and final depth....
kerf width, offset (inside/outside/no offset), = "tool diameter".... just change the diameter and it should change the offset, although "operation type" changes between inside and outside contour, and this should change the offset from inside to outside.... but I'm not sure if this changes the cutting direction too (or how you can change the cutting direction (i.e. clockwise and anti-clockwise)
LeadIn, LeadOut, .... presume that this could be done via macros? (the problem you would have I would have said was to determine which side of the cut the leadin is to be positioned ....., especially with a zero offset.... as you'd still need to tell it inside / outside cut)
And may be add ability to insert macros on corners and on the end of cut?
But then there are other features like over-cut + rotary plasma + leadin from the centre of circles less than 25mm for example...(all built into sheetcam)
But then you have to consider that sheetcam isn't really expensive £110 ~= $135 USD / E122 euro (especially with the £ falling like a stone ~7% in less than a week, and expected to go a bit lower) ..... is it really going to add value to uccnc with a ~ E130 - E160 price tag (including the motion controller), it may be cheaper + time wise for CNCdrive to tie up with Les at Sheetcam for some direct plugin access for sheetcam which is fairly well developed and he handles the bugs well with development releases issued every few weeks with new features etc ..... maybe even a subsidized discount for sheetcam such as that offered via here for bundles + the addon modules without the offer of support etc
http://www.lowcostcncretrofits.com/