I moved to UE 4.8.2 and tried to test the issue again - I changed X location of the subcomponent and Unreal BLueprint Editor crashed right away. Here is the message:
MachineId:DD147B6D4BF10DA828D3BCA15312FE2A
EpicAccountId:412bf6c56b874701a4e16719dc9678c1
Unknown exception - code 00000001 (first/second chance not available)
"Assertion failed: Obj [File:D:\BuildFarm\buildmachine_++depot+UE4-Releases+4.8\Engine\Source\Editor\UnrealEd\Classes//Editor//Transactor.h] [Line: 158]
"
UE4Editor_Core!FDebug::AssertFailed() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\runtime\core\private\misc\outputdevice.cpp:355]
UE4Editor_UnrealEd!FTransaction::FObjectRecord::FPersistentObjectRef::operator->() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\editor\unrealed\classes\editor\transactor.h:159]
UE4Editor_UnrealEd!FTransaction::FObjectRecord::FObjectRecord() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\editor\unrealed\private\editortransaction.cpp:32]
UE4Editor_UnrealEd!FTransaction::SaveObject() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\editor\unrealed\private\editortransaction.cpp:241]
UE4Editor_CoreUObject!SaveToTransactionBuffer() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\runtime\coreuobject\private\uobject\uobjectglobals.cpp:1723]
UE4Editor_CoreUObject!UObject::Modify() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\runtime\coreuobject\private\uobject\obj.cpp:830]
UE4Editor_Engine!UActorComponent::PreEditChange() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\runtime\engine\private\components\actorcomponent.cpp:445]
UE4Editor_DetailCustomizations!FComponentTransformDetails::OnSetLocation() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.8\engine\source\editor\detailcustomizations\private\componenttransformdetails.cpp:1054]