I would try Poseray and check out your 3D text in it's preview. From my experience, if it looks good in Poseray, it will in TG2 too. However, don't expect the colors to match. TG2 is primarily for outdoor renders, so there are many things (settings) you may have to play with to get your text color where you want it.
When I load a model into Poseray for exporting to TG2, there are several things I do each time. They are on the "Groups" tab: Recalculate normals, Weld vertices, Remove orphan vertices, Remove orphan normals, and Remove non-visible groups. I click each one in succession and I rarely have any surprises in TG2 with the model geometry. However, that's using Lightwave, not Hexigon, so you should give it a test.