You put a proper PVC casing to conceal the insulated piping, run it at the edge of the walls. That would be the cheapest & reliable option.

If you want to conceal by hacking, it would be worse.

Ugly = temporary. Use this to motivate yourself that you are going to move out to bigger house in near future.

thats crazy man. the developer might have been better off putting up more decorative metalwork on the other side.

If your pipings are concealed suggest to change whole copper piping
How old is your house?

Reason being there might be multiple leaking point
let's say if you hack your wall and found one leaking point
then you weld back
after few weeks if not cold then you need find other leaking spot
hacking + weld + conceal again
double work.. labor alone will be hefty

Not suggest to do half baked work
the technician also will tell you they will not guarantee.. after repair done
because if the pipe is old and started leaking, potentially other section have same issues or will have same issue soon (almost time)

This also depends on quality and thickness of the copper pipe used by your contractor

Even if you hack the whole pipe to inspect and weld back muitlple leaking spots
don't think the repair will be as good as brand new copper pipe

Just need to ensure your technician using good copper pipe
one time repair and you're good

Even if I moved to house

I plan to use this property for rental

I don't want my tenants to be complaining no air cond.