It looks like it could be worth trying out at least once, given that the server has halloween maps of most other stock maps now. https://steamcommunity.com/sharedfiles/filedetails/?id=2225100906&searchtext=
I put it up, right now the list is as follows pl_hasslecastle koth_megalo koth_undergrove_event cp_degrootcreep_b3 cp_dustbowl_event cp_gorge_event cp_halloween_warpath_4 cp_pacman_plus_wtf cp_sunshine_event ctf_boneyard ctf_darktower ctf_doublecross ctf_hellpower ctf_haunt_b2 koth_maple_ridge_event koth_dropdeadfred_v3 koth_harvest_event koth_lakeside_event koth_lolcano_b3 koth_moonshine_event koth_viaduct_event pd_pit_of_death_event pl_fifthcurve_event pl_millstone_event plr_hightower_event sd_doomsday_event pl_5curve pl_alpen_rc1 pl_angkor_rc2 pl_auriferous_rc28 pl_badwater_pro_v12 pl_barnblitz_pro8 pl_beerbowl_rc1 pl_borneo pl_boundary_final1 pl_boxcanyon_rc9 pl_buzznest_b3 pl_cashworks_final1 pl_clifftop_b3 pl_cornfarm_rc pl_cranetop_b8 pl_deadwood pl_enclosure_final pl_erosion_b1 pl_escarpment_rc1 pl_frontier_final pl_gloryhole_b1 pl_goldheist_canyon_final_v17 pl_goldrush pl_goodwater pl_great_heights_b3 pl_halfacre pl_hatfactory55 pl_haywire_rc5 pl_hoodoo_final pl_humidity_rc5 pl_lionroar_rc1 pl_losthorizon_b8 pl_manngrove_rc5 pl_mesaworks_rc3 pl_metropolis_b5 pl_midwest_b12 pl_millstone_b1 pl_mineshaft_final_rc9 pl_moonbase_rc3 pl_mountainside_rc2 pl_narrows_a130 pl_oasis_b4 pl_olympia_a24 pl_outback_rc4 pl_pharaoh_rc1 pl_pier_b23 pl_quagmire pl_rebirth_rc1 pl_rivercrossing_rc2a pl_rocketravine_b6 pl_rust pl_shoreleave_rc1 pl_sludgepit_final3 pl_snowycoast pl_summercoast_rc7 pl_swiftwater_final1 pl_thundermountain pl_upward pl_vesper_b4 pl_vigil_rc7 pl_volcanic_a26 pl_warpath_b7 pl_waste_v2 pl_yamashiro_medieval_b3 plr_animus_a8 plr_bananabay plr_fishladder3 plr_frostfell_b2 plr_hierarch_rc2b plr_highwind_a5 plr_hightower plr_highertower plr_nightfall_final plr_panic_b2 plr_pipeline plr_snowthistle_b3 plr_solitude_b1 plr_valentine_b2 plr_yuno_b1 cp_abyss_b81 cp_alloy_rc3 cp_amaranth_rc1b cp_antiquity_rc1 cp_arena_trains_b2 cp_axle_rc1 cp_badlands_pro cp_burghausen_rc1 cp_croissant_final cp_degrootkeep cp_desperados_b2 cp_dustbowl_pro_v2 cp_egypt_final cp_ferrum_rc1 cp_follower cp_forest_shrine_a15 cp_foundry cp_freight_final1 cp_furnace_rc cp_glacier_rc6 cp_glassworks_rc6a cp_gorge cp_gothic cp_granary_pro_rc8 cp_gravelpit cp_gullywash_final1 cp_hadal_b13a cp_haddou cp_indulge cp_kakariko_a3 cp_konkreet_b4 cp_kuriast cp_labor cp_mainline_rc5 cp_metalworks cp_mercenarypark cp_miningco_b4_fix cp_manor cp_mossrock cp_mountainlab cp_obscure_remake_ugc_rc2 cp_orange_final cp_orangezone_45 cp_osiris_b15 cp_overgrown_rc5a cp_powerhouse cp_process_final cp_prolane_v4 cp_reckoner_rc3 cp_redfort_b3 cp_rumble_rc5 cp_sakura_hill_72c cp_science2 cp_shelter_rc2 cp_skull_island_b2 cp_snakewater cp_snowlodge_b5 cp_standin_final cp_steel cp_sulfur_rc2 cp_sunshine cp_toy_fort_alt2 cp_treehouse_b4 cp_vanguard cp_vigor_b2 cp_warmfront cp_warpath2_u4 cp_well cp_wetlands cp_whiterock_rc2 cp_yukon_final ctf_2bine_v1 ctf_2fort_egypt_litefin ctf_chaos ctf_convoy_storm_b1 ctf_doublecross ctf_eggwar_b2 ctf_haarp ctf_hotspring_b3a ctf_landfall ctf_mach4 ctf_powerhouse_night ctf_slate_b2 ctf_snowdrift_b4a ctf_turbine_pro_b1 ctf_urbanbrook_rc ctf_vitalism_b2 garbage_day koth_ahau_rc2 koth_arctic_b3 koth_blast_b3p koth_brazil koth_coalplant_b7 koth_coulee_b4_fix koth_chasm_b1 koth_cyberpunk_b2 koth_dewm_rc1 koth_dockyard koth_dropdeadfred_v3 koth_former_cornfield_b1 koth_harvest koth_highpass koth_kemptown_rc1 koth_king koth_lakeside koth_lazarus koth_lolcano_b3 koth_megaman6 koth_moonshine koth_nerve koth_nucleus koth_occult_rc6 koth_viaduct koth_sandvich_b1 koth_sawmill koth_skywalker1 koth_suijin koth_waste koth_wubwubwub_remix_vip mpl_losthorizon_b10 pd_elvvis2 pd_ritual_a7 pd_steamed_hams_final pd_watergate pl_beerbowl_b5a pl_beerbowl_b6a pl_beerbowl_b6b pl_beerbowl_b7 pl_beerbowl_b7a pl_beerbowl_b7b pl_beerbowl_b7c fith_boxing_b2a