If you can let your trail elbow get away and then get it back into the correct position with your trail arm bent as it should be then you don't need to keep it close. If you can't then the advantage of keeping it close is that you have a better chance of getting it done. In my experience (and that of the person I showed the drill) even letting it get away slightly is detrimental to getting it back to where it needs to be even on a short shot.
Obviously I don't know exactly what you did when you tried it but if you don't do it naturally it will feel different and if you are limited in the needed flexibility it may even feel uncomfortable. However if you have your trail elbow as close as Hogan for as large part of the downswing, then a partial shot that starts with your elbow that close should be no problem.
So you either prioritize your emulation of the best golfers to match their top of swing positions with the elbow away while likely having no ability to get it back to where it needs to be OR you can prioritize in favor of having the trail elbow and arm in the correct position.
BTW - IMA Impact Backwards Drill #4 is specifically to train you to get your trail elbow into the correct position and if you do it correctly your trail elbow will not be very far away from your trail side. A bit of 'anatomical certainty' from Scott. Drill #3 is a partial shot where you trail elbow should never leave its position 'on station' until after '6/100s' before impact.