When we say "loosing compression" we are not referring to what you are calling compression loss.

What you show in the video is perfectly normal and indicates an engine with VERY GOOD compression.

Air/Gas will always escape past the cylinders, particularly if there is no piston ring ( as in many ABC engines ) to further act as a seal... and even piston rings have a gap in them that tends to let air through.

The only thing you want to assure is that the air/gas escapes as shown in your video somewhat slowly.

No compression or loosing compression, refers to practically no resistance to moving the cylinder into the cylinder head because ALL or almost all air/gas is escaping very quickly.

I have a few engines that if they are fully dry with no oil or fuel in them after not using the engine for a while, the prop will spin almost freely.

Yet once fuel hits the engine, there is pronounced resistance to flipping over the prop and the engines start and run just fine.

So don't worry about it.

The engine is fine and you've already cured the fuel flow obstruction...

One hint about Evolution engines.

You may see a slight grey goo coming out of the muffler. This is caused by aluminum particulates being shaved off the back cover and other surfaces as the engine wears in. This is perfectly normal for Evolution engines and a few others.

However this grey goo can harden and cover the pressure fitting inlet nipple.

It is a good idea to remove the pressure tube from the muffler at the start of each flying day and stick a small allen wrench down the hole to clear it of any obstruction. Actually it's a good habit to get into with any engine.