Second 'Blynk.virtualWrite' command takes much more time than first one

If I understand correctly, I can only send 10 request per second on single virtual pin.
But I can send 100 request per second to my device, as long as request number on same pin doesn’t exceed 10 request per second.

So, if I reduce interval of timer handler to 100ms, my device should send 30 request per second. (10 request per second on three virtual pin)

But when I run the code, I couldn’t send 30 request per second because timer doesn’t working correctly due to virtualWrite delay.
As you can see the timestamp in the serial, I can only send 15 request per second.(5 request per second on three virtual pin)

#define BLYNK_TEMPLATE_ID "***"
#define BLYNK_TEMPLATE_NAME "***"
#define BLYNK_FIRMWARE_VERSION        "0.1.0"
#define BLYNK_PRINT Serial
#define APP_DEBUG

#include "BlynkEdgent.h"

BlynkTimer timer;

void doVirtualWrite(){
  unsigned long start, end;

  start = millis();
  Blynk.beginGroup();
  Blynk.virtualWrite(V0, 1);
  Blynk.virtualWrite(V1, 1);
  Blynk.virtualWrite(V2, 1);
  Blynk.endGroup();
  end = millis();
  
  Serial.printf("3 virtualWrite Time - Group: %d\n", end - start);
}

void setup()
{
  Serial.begin(115200);
  delay(100);

  timer.setInterval(100L, doVirtualWrite);

  BlynkEdgent.begin();
}

void loop() {
  timer.run();
  BlynkEdgent.run();
}
19:19:15.981 -> [192] 
19:19:15.981 ->     ___  __          __
19:19:15.981 ->    / _ )/ /_ _____  / /__
19:19:15.981 ->   / _  / / // / _ \/  '_/
19:19:15.981 ->  /____/_/\_, /_//_/_/\_\
19:19:15.981 ->         /___/ v1.3.2 on ESP32
19:19:15.981 -> 
19:19:15.981 ->  #StandWithUkraine    https://bit.ly/swua
19:19:15.981 -> 
19:19:16.013 -> 
19:19:16.013 -> ----------------------------------------------------
19:19:16.013 ->  Device:   ***
19:19:16.013 ->  Firmware:  0.1.0 (build Nov 23 2023 19:16:41)
19:19:16.013 ->  Token:     *** - •••• - •••• - ••••
19:19:16.013 ->  Platform:  ESP32 @ 240MHz
19:19:16.013 ->  Chip rev:  3
19:19:16.013 ->  SDK:       v4.4.6-dirty
19:19:16.013 ->  Flash:     4096K
19:19:16.013 ->  Free mem:  243212
19:19:16.013 -> ----------------------------------------------------
19:19:16.013 -> 
19:19:16.013 -> >[235] INIT => CONNECTING_NET
19:19:16.056 -> 3 virtualWrite Time - Group: 0
19:19:16.056 -> [245] Connecting to WiFi: ***
19:19:17.368 -> [1592] Using Dynamic IP: ***
19:19:17.368 -> [1593] CONNECTING_NET => CONNECTING_CLOUD
19:19:17.414 -> 3 virtualWrite Time - Group: 0
19:19:17.414 -> [1603] Connecting to blynk.cloud:443
19:19:19.264 -> [3451] Certificate OK
19:19:19.669 -> [3864] Ready (ping: 411ms).
19:19:19.747 -> [3933] CONNECTING_CLOUD => RUNNING
19:19:19.951 -> 3 virtualWrite Time - Group: 207
19:19:20.152 -> 3 virtualWrite Time - Group: 209
19:19:20.355 -> 3 virtualWrite Time - Group: 207
19:19:20.574 -> 3 virtualWrite Time - Group: 206
19:19:20.761 -> 3 virtualWrite Time - Group: 207
19:19:20.978 -> 3 virtualWrite Time - Group: 206
19:19:21.197 -> 3 virtualWrite Time - Group: 207
19:19:21.382 -> 3 virtualWrite Time - Group: 207
19:19:21.600 -> 3 virtualWrite Time - Group: 210
19:19:21.818 -> 3 virtualWrite Time - Group: 207
19:19:22.035 -> 3 virtualWrite Time - Group: 209
19:19:22.220 -> 3 virtualWrite Time - Group: 207
19:19:22.436 -> 3 virtualWrite Time - Group: 209
19:19:22.654 -> 3 virtualWrite Time - Group: 207
19:19:22.856 -> 3 virtualWrite Time - Group: 208
19:19:23.058 -> 3 virtualWrite Time - Group: 207
19:19:23.264 -> 3 virtualWrite Time - Group: 206
19:19:23.483 -> 3 virtualWrite Time - Group: 207
19:19:23.653 -> 3 virtualWrite Time - Group: 206
19:19:23.897 -> 3 virtualWrite Time - Group: 208
19:19:24.084 -> 3 virtualWrite Time - Group: 208
19:19:24.304 -> 3 virtualWrite Time - Group: 207
19:19:24.508 -> 3 virtualWrite Time - Group: 207
19:19:24.726 -> 3 virtualWrite Time - Group: 207
19:19:24.929 -> 3 virtualWrite Time - Group: 208
19:19:25.145 -> 3 virtualWrite Time - Group: 205
19:19:25.331 -> 3 virtualWrite Time - Group: 210
19:19:25.561 -> 3 virtualWrite Time - Group: 209
19:19:25.748 -> 3 virtualWrite Time - Group: 207
19:19:25.966 -> 3 virtualWrite Time - Group: 207