Regarding climbing above the original redirection point on SRT...
Suppose you're climbing a Doug-fir. If your rope is a bit woven between branches initially, you have multiple TIPs/ Redirection Points, since there is no need to isolate the TIP.
When you get to the top RP, and want to go higher, just choose your path so that you continue adding to the existing string of redundant TIPs/ RPs. If it is difficult to maintain the integrity of the TIP due to where you need to climb, you could just lanyard in, and unclip the SRT system, and pull it a full revolution around the limb, though this will potentially add a lot of friction for when its time to pull the rope.
I had to get some widow makers from some tall firs the other day. Shot a line to about 60' to the first branch. When I got there, I lanyarded-in around the trunk, over a large branch for fall protection, and got on top of the branch. While maintaining the SRT, I used my tail as a DdRT system, with my lanyard, to move up to 80' (there were no sizable enough branches to use to redirect the SRT between 60' and 80', mostly dead stubs. At 80' I climbed over another large branch, returning my weight to my SRT system, anchored at the ground still. Being done with the deadwooding in tree 1, I lowered down to swing into the next tree from the tree 1, keeping my system anchored in the tree 1, but redirected in tree 2. I was able to lower down and deadwood tree 2 as much as was needed.
If this isn't coming through clear, I can get a better picture. It hard to write out.