ANYTHING is "warfable", provided you have the time and money, or if you have the machines, knowledge and skills.
The real question is "is it worth warf-ing".
WARF-ing started using a rather narrow specific selection of ex-early generation compound risers--mostly Hoyts and Bears (or clones thereof). Moving out-side that group things get "iffy" fast.
The length, weight and geometry all have to be factored into the decision. Some, very bluntly, are not worth the effort and/or cost involved. Too many ex-compounds, even if totally free or a favorite old hunting tool are simply not good candidates.
Your best bet is to consult with one of the experienced guys who are doing it on a professional or semi-professional basis. Listen to their opinion and pay them to do the job properly.
Many of us have gone the DIY route, except for the few who are machinists with access to the proper tools, most of us learned to put it in the hands of the pros.