I had a few 32 bit plugins that worked OK in Sonar x64. Eventually found replacements though.
I think (anecdotally) that the further we get from the start of the x64 era the less stable a system will be running 32 bit plugins. Cakewalk introduced 64 bit Sonar in 2005 with Sonar 5, 10 years ago. Windows 10 seems to be most frequently loaded on new PCs as 64bit.
As an example. Pro Tools was the last major DAW to come to 64 bit and is only available as 64 bit program now.
I think the trend is for software to be written to use more and more resources making 64 bit software more and more necessary.