Мини-турнир "Caribbean Sea"

Is it possible to first complete a map on an easy difficulty level, and then, using a save file, play it on a harder difficulty level? So that I can earn more points later...

Of course, you can! Understanding the essence of the playthrough is the key to success ;)

Added 1 minute ago

I just sent the save file; the map wasn't difficult, but it was interesting.

Your save file has been received ;), and all the information is in the table.

Added 7 minutes ago

Before participating, I would like to clarify:
1) Is the game only playable on version SoD 3.2, or also on other versions (this is quite an important point);

Since the bugs have been fixed in SoD, SoD 3.2 is the "standard," but you can use Platinum as well, although without taking advantage of this version. Since there is a possibility of requesting additional save files due to suspicion of cheating, it is better to avoid such "thoughts" ;)

2) Can navigation bonuses be used in any of their forms?

Exactly. The main thing is not to use the technique deliberately.