While there is no button to click to turn off spec breaks in AutoCAD Isometrics, you can do it via the xml.
Locate the Default theme AnnotationsScheme for your style’s isoconfig.xml.
The easiest way is probably to do a search for SpecBreaker. Under SpecBreaker, you will have to add an Enabled attribute like so:
Generating your iso again will change this:
to this:
