Is a problem with MT4 terminal. Is a very old SW and in the single thread. But this problem take up with version 2.xx.n. In the older version is without problem. I also trying the SET(LOCK/UNLOCK) and unaffected.
On a VPS:
1. start one MT4 terminal with zorro plugin
2. start more Zorro script / each diferent / with MT4
3. terminal MT4 - react very slow,
4. close all Zorro script except one - MT4 still not react ( I trying get terminal to front - no work )
5. close last Zorro - MT4 work without problem
maybe is a problem with grafic card on the VPS.
Run more instance MT4 is now very good, consume lots of RAM and CPU
edit:I try with other VPS - and is better.
WIth other VGA, MT4 not frozen, and react normal!