I'm just logging this here as it seems to be a change in behaviour between 19.1 and 20.0, not a surprise because a huge amount has changed

I'm afraid I can't give you a reproduceable sample only what is appearing to happen as it is a combination of a lot of small things as opposed to where you can step through the code and go ah! that is the cause

We have a class that Set_Argument_Size (50*1024*1024) in the construct object and sets it back in the destroy

Obviously this is global and whilst it is set then things like opening a view with a significant number of tab pages takes a good number of seconds longer than if the argument size is not set. Maybe a couple compared with a good six seconds

19.1 opens the view at the same speed with/without Set_Argument_Size

Removing tab pages to see if it affects one more than others and it doesn't it's a very cumulative effect

Simply putting Set_Argument_Size in customer.dd in OE doesn't seem to have a significant effect as you would expect

I know there was some talk/desire of trying to remove the need for Set_Argument_Size but that it would have to wait for a future revision

I will look to mitigate it but I'm really just putting this out there just in case you are aware of things with Set_Argument_Size that might affect performance in 20.0 compared with 19.1