I don't know the details of the evernew nonstick Ti pots. I assume it has a teflon coating. If it does, this is a major handicap to attaching a useful heat exchanger.
While some expoxies are more thermally conductive than others, you may have discovered that none of them approach the conductivity of metals (even low conductivity metals like Ti). A heat exchanger attached with epoxy won't make a significant difference in your fuel consumption or boiling time. The epoxy just isn't conductive enough. The exchanger will weigh far more than any fuel you'll save.
The teflon coating is a problem because you can't use a high temperature process to attach the heat exchanger. Silver solder would be ideal because, done right, it can give a strong bond between dissimilar metals, it retains that bond strength at high enough temperatures, and it has a very high thermal conductivity (probably more than 100x that of epoxy). But, the heat of soldering/brazing will ruin the nonstick coating on the inside of the pot.
If you really want to attempt a DIY heat exchanger pot, I would choose another pot and try soldering/brazing.