I've done loads of occupied domestic rewires and I can say that pulling down existing conduits/capping/oval is 100 times quicker then sheeting up the owners furniture chopping out their walls dusting the house, bagging up the rubble etc.
I've never in my life had anyone do the chasing/strapping for me, always had to do it myself and I still always underestimate how long the tidy up take.
ive never been self employed so i do not know what that is like, i suppose concrete walls is common in tower blocks now that i think about it, solid floors and roofs too
on the new build flats ive done the floors and roofs are strapped out, cables in the roof, pipework in the floors for the most part
everyone has their own way of doing things that works for them, some guys strip T+e totally different to how i would do it but its what they are used to, showed an older guy how i just snip up the earth, grab it and pull it to strip and he was amazed how quick it was compared to a stanley/pocket knife
only kitchens and bathrooms would be strapped out, full rewires id try my best to do everything from the floorboards and roofspace/crawlspace, path of least resistance applies to more than just electricity
spanish guy i work with says in spain the houses are all done in conduit, but in singles and in a way that is easy enough to route cables through them in future
if the customer wants a new socket though youre going to have to chase the wall, so mess is sometimes unavoidable , most people tend to add on extra points when re-wiring since they have the option at not much extra cost