According to correspondence in the Olmsted Brothers archives, Mackenzie spent about one month on property in March 1932 to oversee the final contour work on the greens.
Additionally, regarding the trees and shrubbery, in September 1931 Berckmans inventoried the property in detail, noting specific varieties on topographical maps used by Mackenzie.
Regarding the relocation of trees and shrubbery, more information below.
Although Mackenzie spent a shockingly brief time (IMHO) on property routing the course, and though he did not see the opening day course, this was not a drive-by operation. Unless major changes were made after March 1932 without his knowledge or permission, he would have known, down to specific locations of specific fauna, in great detail what his course looked like.
One possible exception are the fairway mowing lines: Mackenzie and Jones gave explicit instructions there should be none but Olmsted Brothers' drawings and topos sketched in fairway mowing lines, of which Wendell Miller, Mackenzie's project manager, approved:
"I appreciate very much the assistance you have given Mr. Berckmans in the matter of fairway outlines. As you probably learned from Mr. Berckmans, both Mr. Jones and Dr. Mackenzie are of the opinion that we should continue to mow all of the area which was seeded to fairway length but I, personally, think that the course will look better if a definite outline is given to the fairways. Your delineation of the fairways seems to be correct with the exception of a few minor changes which I have noted on the plan." -- letter dated 1 November 1932 from Miller to Olmsted Brothers.
Trees and shrubberyExcerpt of trip report from Olmsted Brothers partner William Marquis dated October 4-7, 1931
Source: Olmsted Associates Records, Manuscript Division, Library of Congress, Washington, D.C.