App installing takes a long time in a Work Profile Having MIUI optimization enabled on a MIUI device (for me: Mi Max 2) makes it to take a long time (exactly 10 minutes) for each new app to be installed. Although I have not seen such behavior in the main profile/user, in a Work Profile (i.e. managed profile) with MIUI optimization enabled, each installing process takes exactly 10 minutes.

However after turning off the MIUI optimization (under Developer options), this behavior does not happen. Has anyone notified of this behavior? What is wrong with the MIUI optimization? Can I get rid of this optimization without getting into trouble in other parts of system?
There won't be any real damage when you  turn off MIUI optimisation.

This post describes the effects of having MIUI optimisation turned on/off as reported by MIUIers.

The optimisation offers some MIUI based settings &amp; optimizations set by developers with aim of giving a fast user experience but of late has offered more disadvantages especially in new ROMs. 

It has been reported to cause some some incompatibility issues with Google based apps and sync services and also non functionality of Greenify hibernate feature in non-root mode (MIUI 9.xx) althought it doesn't affect MIUI 8.

Therefore, you can safely turn it off, if it is causing lag issues With work Profile, as much as it is recommended to be off when using Greenify (MIUI 9). Besides the changes described in the linked post (as a MIUI user) I don't see any detrimental effects when you disable it.