On 2 servers with real players, out of 6 Steam servers that run it now, fakes and empty ones included. Checked 18:26 UTC.
kzpro_only_up_extended is a community map, not one of the maps that come with the game. Servers send it to players from the Workshop when they join.
Over the last 30 days kzpro_only_up_extended was the #727 map on CS2 community servers, with 2 real players on it at any moment on average - 0% of everyone playing. It ran on about <1 servers with real players at a time. Right now 5 people play it on 2 servers, most of them on servers in Russia and Poland. It is busiest on Sunday around 17:00 UTC and quietest on Monday around 02:00 UTC.
Right now 5, on 2 servers from the Steam server list. Over the last 30 days it had 2 real players on average at any moment. Fake servers and bots are not counted, and Valve matchmaking is not in the list.
On Sunday around 17:00 UTC. The grid above shows every hour of the week in your own time zone.
The busiest right now: CS2 KZ #293 [RU] — CYBERSHOKE.NET (TIER 1-3 - EASY) (3 players), XPLAY.GG • CS2 Matches #1106 (2 players), XPLAY.GG • CS2 Matches #441 (0 players). The full list is under "Servers running it now", and every server has its own page with its history.
de_mirage43,391 players on average
de_dust217,971 players on average
sandstone_fb14,482 players on average
de_mirage_fps6,350 players on average
awp_lego_25,460 players on average
awp_lego_2_fb4,843 players on average
de_mirage_christmas2,864 players on average
<null>1,275 players on average
bhop_emevaelx31,058 players on average
duels_mirage_1x11,023 players on average
de_inferno891 players on average
de_nuke748 players on average
RU
PL