Chips don't really change that much.

An evo chip will probably retard the ignition at higher boost/rpm, remove the boost limit etcetc. or something similar. Its not doing a great deal, its changing something that already works.

A base map isn't safe to start with, won't work really well etcetc, and every engine will require slightly different trims and values for the same spec, no two engines are the same, your not making small generic changes to something that works.

Its likely a base map for one car will work well on another but the final map could look very different.

Rob,