V5 and V6 incompatibility

We have a significant code commitment to DHTMLX v5.x, which we need to maintain.
After looking at v6, it became clear that all this code would need to be rewritten.
Our strategy was to incrementally move to v6, one piece at a time.
Unfortunately, it appears that we cannot have v6 and v5 (for the legacy javascript) loaded at the same time. They are incompatible.
I think I know the answer, but would it be possible to have suite.js and v5 dhtmlx tree grid coreside in the same browser session?

Unfortuantely it is not available to use the dhtmlx 5 and dhtmlx 6 on the same page.