So even though we couldn't run marks without assistants, I took him to the nearby, recently closed golf course, and we went for a long walk to run blinds. I wore white jacket and black gloves (I'd like to recommend Gorilla Grips gloves from Home Depot for anyone interested), and carried along a lining pole and three 2" orange bumpers, though it turned out I never used the lining pole and only needed one bumper.
As we walked, I'd locate a blind I'd like to run Laddie on, place the orange bumper, and then continue walking till we reached the start line I wanted to use.
Laddie also kept active running after his 2" white (puppy) bumper, which I'd throw as we walked and also as Laddie was en route back with the blind retrieves. Those throws were in effect bulldogs, but as far as I know bulldogs aren't used in field trials and I don't plan to run Laddie in any more hunt tests, where bulldogs do occur. We do them just for fun and perhaps to somewhat tune Laddie's marking focus and memory.
Laddie ran a total of about a dozen blinds, varying in distance 150-300y+, and with a wide variety of orientations (wind direction and sun placement) and other factors (including mounds, keyholes, branches to climb over, treelines to run past and avoid wrapping around at the end, channels, and shoreline swims).
Here are photos of a couple of the blinds:
210y water blind across channel with fast RTL flood-waters, past clump of reeds with wrap suction to left, then pond re-entry with suction to left, swim across corner of pond with suction to left, angle exit with squaring suction to left, thru land keyhole under tree branches with open-space suction to left both before and after tree, short land segment to reeds at back of last point (zoomed focus)
180y land blind along a treeline, with wrap suction to the left at mid-point and at the end
The only other time I needed to re-run him was on a relatively short blind (no photo) across the corner of a pond, with a large branch on the far shore for Laddie to climb over before completing the land segment to the blind. Laddie repeatedly squared the water entry, no matter how carefully I lined him up, and each time, I called him back. Finally, I left him in a sit and walked to the blind. There I picked up the bumper, showed it to him, and dropped it back to the ground. When I returned to run him for the last time, he again took a squared entry into the water, but not too bad, and handled easily to the blind, scrambling over the branch without difficulty.