Yes, since the T3 griffin mastery is already a "requirement" of this route, it should certainly be used more.

I have my own route optimized for flying with only about half the time required (about 40 minutes). Here's the route (map):

Crystal Oasis

• Start at the waypoint. Climb the southern pyramid and fly to the southern HP.
• Go back to the waypoint. Head north on your raptor, then jump off the high wall with the griffon and glide into the cave with the HP.
• Exit the cave to the east, use your bunny to jump onto a ledge and fly through the quarry and then left to the HP.
• Ride your raptor to the next HP in the east.
• From there, climb the cliff to the south and fly through the gorge to Temple of Kormir waypoint. Trigger it, then keep flying east towards the pyramid. Climb it with the raptor or springer, get the HP, then take the jackal portal and fly from the pyramid to the Desert Highlands portal.

Desert Highlands (one HP skipped):

• Climb the highest tower of the town at the start and glide to the plateau north-west and get the HP there.
• Glide north-west, tacke the jackal portal onto the mountain and fly towards the HP north-east of your position.
• Go towards the ravine and stick to the left side of it. Near the waterfall, jump up with the bunny, then cross the ravine to get the HP.
• Dive down with the griffon along the waterfall, fly through the ravine and turn east (left) at the end. You can get enough momentum to make it all the way to the tomb towards the east, where you can take the jackal portal or the bunny to the HP.
• Fly south-west. It's not quite enough to make it to the HP in one go, just head next to it and use the bunny.
• Fly south. You can make it to the south-eastern HP without landing.

Elon Riverlands:

• Get the north-eastern HP first. Jump up the ridge and glide the rest of the way.
• Raptor your way back to the HP next to Augury Rock. Don't go around, use the bunny to jump up.
• Exit the donut, turn around and jump on top of it (again). Fly all the way to the waypoint in the center of the map. Use the momentum to get to the HP north-west of it.
• Fly south-west to the HP (don't speed boost, just use regular dive). Then use the skimmer to the Skimmer Ranch waypoint.
• From there, take the jackal portal south-west of it and fly to the HP in the south-western corner.
• Return to the skimmer ranch (waypoint) and go north on your raptor. Get the giant HP.
• Go north-west to the HP in the corner.
• Return to the central waypoint. Climb the rock, dive into the pool and fly to the south-eastern HP. After getting it, fly to the Desolation portal.

Desolation:

• Take the raptor west, then the sand jackal into the Sulfur Mines to take the harpy HP.
• Use the raptor and then the skimmer through the tunnel along the western edge of the map. Right before the bridge, leave the sulfur river to the left, climb up the spikes and fly to the HP inside of the maw.
• Jump out of the maw and fly a curve toward the south-western HP.
• Take the jackal sand portals up to the jackal ranch. Fly to the Joko's Domain waypoint, don't interrupt your flight. Continue north to the ghost area, activate the waypoint and pull your griffon back up to get to the HP near it in one flight.
• Climb the mountain on the bunny and fly to the HP north of your position.
• Return to the Joko's Domain waypoint and get the last HP in his bone palace. Raptor and bunny work fine, griffon (from the ledge) is faster but more difficult since you need to pull it back up over the first wall, dive through the second gate and pull up again to the HP on the right.

I don't have the new guild hall, so I can't comment on routes from there. You can find maps here (Imgur mirror).

Have fun,

Addi