I am not a big fan of mixing sprinklers, but in some cses I have used them for upgrades. It is always great to follow installers that do not get full coverage. What a waste of time to do an install only to not have coverage in certain areas. Most of the time I will go in and add some gear drives to compensate for the lack of coverage. It is do this or nothing as the installer has already hit them hard in the wallet. Some systems were put in by the homeowners trying to save some cash. Do the upgrade and get it up to code, then watch the look on their face as you hand them the bill. Better off if they had used me in the first place. Some people will never learn.
Sanity, is on the verge of DULL.