starting mapping question

Still pretty new to the game, and just getting ready to start mapping in ambush. About how many lvl 66's do you want to have in your stash before you start, so you don't run out and have to go back to piety farming?

Well, lets say 5 66 maps first and roll each map to get pack size/extra magic/double boss. You can also go farm docks, you may get lucky with cartographer box like I did, 26 maps.

I never run out of 66 maps once I started mapping. These drop pretty frequently really.

I just ran my 66s white since my characters were pretty weak at the start of ambush. You can indefinitely sustain low maps even with only white maps, especially since ambush has generous strongboxes.

Generally if your new to mapping then sure 66 are okay, however what most people do is just run piety/lunaris, gets maps, get 3 of a kind, then trade them for a 67 map recipe. Repeat and move up the map ranks. I wouldn't waste my time with 66, not because you don't get higher maps from them, but because they generally don't give better drops then simple lunaris runs, and same exp if not less.

Otherwise, get 5, start. Getting an entire row vertically would be best to start if you plan to get higher maps, and can clear them relatively fast (within 10 min).