Bitbridge is just that, a bridge not only between the 32bit plugin and the 64 bit host host, it's also a bridge between moving from 32 bit 64 bit completely.
I don't think Cakewalk will develop the technology any further as you can easily install both the 32 and 64 bit versions of Sonar concurrently.
Bitbridge is not effective with very plugin. Many of us also use a program called jBridge which costs about $20. If 32 bit plugins are so important to you then perhaps it's worth the price of entry. It has far greater flexibility than Sonar's Bitbridge and can be set as the default bridging software on a per plugin basis from within Sonar.
Very few modern plugins don't have a 64 bit version yet and with the ever expanding formats that developers have to code for I can see a time when some formats will get dropped. Now we have VST 32 and 64 bit for both VST 2.4 and VST3 then there is RTAS for Pro Tools pre PT 11 and AAX 32 and 64 bit for ProTools 11 and onward and that's just for the PC. Add to this the Mac and it's starting to get quite complex.
The best advice is to run 32 bit Sonar for those few older plugins if bridging doesn't work and migrate to full 64 bit. Either that or stay completely 32 bit and deal with any memory restrictions that that implies.