Voting for the location of the CIS-2107 tournament.

limit the maximum points for a single vote to 2 (it was 2 or more in version 2).

This is the most reasonable suggestion. I propose the following:
Not attended any CIS events - 0.5
Attended 1 CIS event - 1
Attended 2 or more CIS events - 2
It's simple, clear, and avoids significant imbalances. Multiple choices are needed for a smoother distribution of votes. If someone wants to attend point A or B, but not C, they should be able to vote that way, rather than choosing the option that scores higher just to prevent C from winning.