I tried using 2022-04-6ragexe and kRO 2023-04-04, ran updater, applied translations + all options, and patched the client. This solved the crashes. Other ragexe/client combos didn't work, so I guess this is probably the most stable one from every map I've felt like testing.
NEMO patches for the curious:
3 Chat Flood Remove Limit
8 Custom Window Title
9 Disable 1rag1 type parameters (Recommended)
13 Disable Ragexe Filename Check (Recommended)
14 Disable Hallucination Wavy Screen (Recommended)
16 Disable Swear Filter
18 Skip Service Selection Screen
20 Extend Chat Box
21 Extend Chat Room Box
22 Extend PM Box
23 Enable /who command (Recommended)
24 Fix Camera Angles (Recommended)
32 Increase Zoom Out Max
34 Enable /showname (Recommended)
35 Read Data Folder First
36 Always read msgstringtable.txt (Recommended)
38 Remove Gravity Ads (Recommended)
39 Remove Gravity Logo (Recommended)
41 Disable Nagle Algorithm (Recommended)
44 Translate Client (Recommended)
46 Use Normal Guild Brackets (Recommended)
47 Use Ragnarok Icon
48 Use Plain Text Descriptions (Recommended)
49 Enable Multiple GRFs (Recommended)
53 Use Ascii on All LangTypes (Recommended)
64 @ Bug Fix (Recommended)
65 Load Custom lua file instead of iteminfo*.lub (Recommended)
69 Extend Npc Dialog Box
73 Remove Hourly Announce (Recommended)
74 Increase Screenshot Quality
84 Remove Serial Display (Recommended)
90 Enable DNS Support (Recommended)
213 Disable Help Message on Login (Recommended)
215 Increase Map Quality
216 Hide Cash Shop
230 Always load Korea ExternalSettings lua file (Recommended)
231 Remove hardcoded address/port (Recommended)
232 Restore old login packet (Recommended)
242 Disable kRO Site Launch
270 Change AchievementList*.lub path
271 Change MonsterSizeEffect*.lub path
272 Change Towninfo*.lub path
273 Change PetEvolutionCln*.lub path
274 Change Tipbox*.lub path
275 Change CheckAttendance*.lub path
276 Change OngoingQuestInfoList*.lub path
277 Change RecommendedQuestInfoList*.lub path
278 Change PrivateAirplane*.lub path
290 Hide build info in client (Recommended)
291 Hide packets from peek (Recommended)
313 Change MapInfo*.lub path
322 Case-Insensitive Storage Search
326 Disable OTP Login Packet (Recommended)
328 Enable 44.1 kHz Audio Sampling Frequency
348 Send client flags to server (Recommended)
351 Translate arrows buttons text from korean to english
404 Use borderless mode in full screen (Recommended)
409 Add close button to game window
427 Check is servertype in xml file was set to correct value (Recommended)
432 Disable Game Guard (NProtect) (Recommended)
436 Disable packets id encryption
441 Draw text messages always with bold font
