Fortunately, Prof. Presas wrote about disarms against the 2, 4, 7, and 8 strikes in his little yellow book, Modern Arnis.
Disarm Against Strike #2:
1. As your opponent attempts a high backhand strike to your head, sidestep to your left as you execute an outside block with your stick while keeping your left hand ready to scoop inside your opponent's right forearm.
2. Wind your left arm quickly in a clockwise direction (6 o'clock to 12 o'clock) until his stick is pressing against your left forearm and his right wrist is pinned under your left wrist.
3. Continuing the pressure will force him to release his stick, and will keep your opponent open for a counterstrike.
Disarm Against Strike #4:
1. As your opponent attempts a high backhand strike to your right side, sidestep to your left as you execute an outside block with your stick.
2. While keeping your left hand on his right wrist, quickly force your stick over and underneath your opponent's stick, raising his right wrist up until your stick and your left hand are both pressing against the back of his wrist.
3. Force your opponent down with strong pressure until he lets go.
These are very similar to how I was taught. I'm not sure if these are new for some, or if I'm just suggesting techniques most people know, as these were taught to me as basic disarms:
Strike #2 disarm:
#1 and 2: Similar to Mcura up to step 2, but instead of pinning his wrist, you pin his elbow and press down with your palm and leverage your body weight. Rather than having his stick pressing down on your forearm, try to get the bottom part of your forearm underneath his wrist so your forearms are intertwined, with his arm twisted so his elbow is facing up and pinned by your palm and his grip is facing up, stick pointing horizontally away from you. This position should be an armlock, so leverage your weight appropriately.
3. Come down on his tricep with the butt of your stick. (if unarmed, use your right elbow instead)
4. Still maintaining the arm lock, reach over and grab the end of his stick, pulling it free from his weak grasp.
Strike #4 disarm:
1-3 Same as the above disarm.
4. Bring the stick horizontal and grip the end with your other hand, keeping him in the arm lock with your stick locking on his elbow. (if unarmed, use your right forearm, gripping your right wrist with your left hand and bearing down to get the right leverage. I actually find this easier to do than with the stick)
5a. (Optional) Leverage your weight to break his arm at his elbow.
5b. Pull back sharply along his arm. If you're in the right position, your arm and stick (or both arms, if without the stick) should strip his stick from his hand.
These are both a little slower than your #2, but I do love that arm lock and break.
I also know your version of the #4 disarm, it's one of my favorites.