CFD vs "Computed text": CFD wins if many items are needed

Hi

Recently I worked on Notes-form that had to be really dynamic regarding displaying different fields for different conditions: changing of one field might hide or show a bunch of other fields and field labels also could be different for different conditions.

At first I used Computed For Display fields to compute and display field labels.
Everything was more or less OK but later I thought that probably it was a bad decision to use CFD fields instead of <Computed Fields> because:

• there is a limitation of 64Kb for all fields with flag isSummary=True (works for CFD also);
• Domino Debugger can show only 255 items so excess of CFD fields could prevent me from seeing other needed items during debugging;
• it makes harder to analyze fields in a document properties window when it's open in UI;

So I decided to get rid of CFD fields and replace them with <Computed text>.
I did it but discovered with surprise that there was a huge gap in performance when I changed document mode from read to edit .

I made a test database and attached it here. If you check it you will see that documents, containing the same number of CFD fields or <Computed text> items, take similar time on opening but critically different time on mode changing - approach with CFD fields works much faster than with <Computed text>.

I have no idea why and I do not see any reasons why it should work like that. Eventually I had to revert my solution back and used CFD fields.

Release 9.0.1FP2 SHF63

Some screens: