I do not know what a "simulated user" is, but more than two users can connect to my OpenVPN server simo.
I just did it, here is a somewhat redacted log.
Tue Jan 25 11:06:26 2022 [my ip goes here]:36597 TLS: Initial packet from [AF_INET][my ip goes here]:36597, sid=6cf19f7a efad9ffe
Tue Jan 25 11:06:26 2022 [my ip goes here]:36597 peer info: IV_PLAT=linux
Tue Jan 25 11:06:26 2022 [my ip goes here]:36597 Control Channel: TLSv1.3, cipher TLSv1.3 TLS_AES_256_GCM_SHA384, 2048 bit RSA
Tue Jan 25 11:06:26 2022 [my ip goes here]:36597 [user1] Peer Connection Initiated with [AF_INET][my ip goes here]:36597
Tue Jan 25 11:06:26 2022 user1/[my ip goes here]:36597 MULTI: primary virtual IP for user1/[my ip goes here]:36597: 10.8.0.4
Tue Jan 25 11:07:02 2022 [my ip goes here]:57523 TLS: Initial packet from [AF_INET][my ip goes here]:57523, sid=69b97549 40baabd4
Tue Jan 25 11:07:02 2022 [my ip goes here]:57523 peer info: IV_PLAT=android
Tue Jan 25 11:07:02 2022 [my ip goes here]:57523 Control Channel: TLSv1.3, cipher TLSv1.3 TLS_AES_256_GCM_SHA384, 2048 bit RSA
Tue Jan 25 11:07:02 2022 [my ip goes here]:57523 [user2] Peer Connection Initiated with [AF_INET][my ip goes here]:57523
Tue Jan 25 11:07:02 2022 user2/[my ip goes here]:57523 MULTI: primary virtual IP for user2/[my ip goes here]:57523: 10.8.0.9
Tue Jan 25 11:07:18 2022 [my ip goes here]:51017 TLS: Initial packet from [AF_INET][my ip goes here]:51017, sid=755ef9f6 7ed60567
Tue Jan 25 11:07:18 2022 [my ip goes here]:51017 peer info: IV_PLAT=linux
Tue Jan 25 11:07:18 2022 [my ip goes here]:51017 Control Channel: TLSv1.3, cipher TLSv1.3 TLS_AES_256_GCM_SHA384, 2048 bit RSA
Tue Jan 25 11:07:18 2022 [my ip goes here]:51017 [user3] Peer Connection Initiated with [AF_INET][my ip goes here]:51017
Tue Jan 25 11:07:18 2022 user3/[my ip goes here]:51017 MULTI: primary virtual IP for user3/[my ip goes here]:51017: 10.8.0.5