Can TIME-SERTs be installed in blind holes?

Yes TIME-SERTs can be installed in blind holes.
A basic dimension we give is .250 inches or 6.3mm deeper hole, than the insert itself.
This is the relief angle length of the tap we have to account for to get a full thread. 
This can vary as small taps will have shorter relief angle length than larger taps. 
Again this is the length from the tip of the tap to the first "full" thread.

The extra depth also gives us enough room for the install driver to slightly pass thru the bottom of the insert to expand the last few threads, locking it in place.
Example.  The blind hole depth for a 5/16-18x.450 should be a minimum of .700 inches or 17.8mm deep.
Insert length .450 + relief angle of tap .250 =.700 inches or 17.8mm Hole Depth. 

Another thing to keep in mind when repairing a blind hole application is that you "do not" want to bottom out the driver tool on installation. There is a simple method to safeguard against bottoming the tool out, by placing a visual mark the driver tool. 
BEFORE installing the insert, place the driver tool into the hole and mark the tool at the point it can't enter any further. Use a ink marker or even use a small strip of electrical tape around the driver. This way we know exactly how deep the hole is and there is no danger of bottoming the tool out.