Difficult to say. Probably the Sony converter would work with a 3rd party lens but there may be an issue of communication. Dedicated OEM converters, I believe, report the effective aperture and focal length (ie the set value multiplied by the conversion factor) back to the camera (for EXIF data etc). Obviously this is fine with the OEM lens but if the data from a Sigma (for example) is not an acceptable format for the Sony converter to work with problems may ensue - a bit like the communications issue between older Sigma lenses and later Canon digitals.

Again you'd have to be very sure of clearance between the lens' rear element and the converter's front one...

Cheaper converters like the Teleplus simply pass the lens data straight through to the camera so there's no question of data failure and the suchlike - though this means you may have to guess which images you used the converter with. Cheaper converters also tend to have recessed elements which makes them compatible not only with the fancy expensive lenses but also with all the mid-range and budget models too.

Also because they don't recalculate the lens data the camera won't disable the AF system if the effective aperture is too small - <f5.6 or 8(depending on model) - meaning that the camera will try to autofocus even if the effective aperture is way too small. I have a Teleplus MC7 2x and have used it successfully in AF with an F4 zoom - a proper Canon converter would have disabled the AF...

In the end you pay your money and make your choice: matched converters such as the Sigma and Sony ones offer the best retention of image quality and pass accurate info back to the camera, but on a restricted range of lenses, while the cheaper ones will degrade the image more but are AF and mechanically compatible with just about every lens - though you will have to guess the effective aperture etc...