Chiveman did a nice Photoshop for us with the Block 185 Tower included into The Republic rendering. Block 185 (left) and The Republic (right).
Of course, missing from this rendering is 6 X Guadalupe, Block 71 Tower, 300 Colorado, 305 Colorado, and The Avenue.
Block 185 and The Republic will beat the Frost Bank Tower for tallest office building in Austin. Block 185 Tower today would be Austin's 3rd tallest.