Actually I have been able to do what I wanted in the meantime.
I incorporated a column in the main Projects table, named [Hide From] with a valid if expression using a select function that points to the useremail column in the ‘user records’ table and lets me select the ones that I want.
Then I created a slice from the “Projects” table with a filter like this:
IN( useremail(), [Hide From]) = FALSE
That filters out the users from seeing the particular row.
Now the concerns that I have regarding this:
My own useremail() comes in the list along with the others’. It may be a good idea to be able to hide that.
It would be good to be able to select the users based on their names rather than the emails (only when those comes in the list).
I suppose both of these shouldn’t be mandatory for flawless running.
EDIT: I’ve just encountered a major flaw. The project is still showing up in the dropdown list in contingent forms where it is required to have a record of the project name. How do I correct this?
RE-EDIT: Stupid of me again, the reference table would have to be the slice itself that I corrected.
Pardon for putting up a question and finding a solution myself, but this could be of help to potential solution seekers of similar problems.