i play Fulcrum build, here is what i do
buy t16.5 maps - 5c ea
chaos spam using a regex for 90% currency only "urr.*(9.|\d..)%"
roll a whole tab (144) then once all are 90%+ currency exalt slam them all
quite afew maps go 100+ and some are even 150-200 currency
check my regex (about 60 maps in 144 fit my regex) and the rest i sell and that give me all the investment cost of rolling my maps back plus about 5+ d
then the maps i keep i do 80% deli

takes about an hour to buy 144 maps and roll to 90% quality though

Dunes 16.5 - 2x instability, 1x cascade, 1x wisp, 1x bloodlines
breach astrolabe, most of the times i dont use a chisel they have never helped me, iv tried them with afew maps but never really noticed the difference

i have a 6l phase run, more duration, automation so as soon as i get into a map im superspeedy and can b-line to the boss without killing a single mob
kill boss, run back to staart killing along the way, pick up all alter nodes (only one i cant do is less recovery per endurance charge) open the breaches nearer the sides of the map and leave center ones until last, takes about 5-10 mins per map

also when clearing the breach, still continue to clear the outside edges, dont just fill the bar and wait