Tip: You can use Lunar Magic's Overworld Layer 3 Editing system to edit or create your own layer 3 images (castle bricks, fish, rocks) and apply unique effects per level via the Layer 3 Bypass in the main editor.
This patch allows each individual (vanilla) dragon coin to be saved once it's collected. Unlike the other method, you don't need to replace all dragon coins with 5 different custom objects for every level. Refer to the comments in dcsave.asm and sram_instruction.txt for details.
Now compatible with LM 3.00 (as well as 2.5x) and the retry patch as requested.
Fixed a bug that the patch refers to $13BF before it is updated properly. Thanks goes to flabort for reporting this.
JackEdit: Added option for only saving when the midway point is collected (needs 8 bytes of freeram more) and to disable the transparent blocks if you'd rather have them not appear at all like the vanilla game.
I seem to be getting the same issues reported by Romano, Good news is I found what seems to be the problem. The patch seems to work fine if the level with the yoshi coins is within certain sub-maps but not others, the problems mentioned also appear in the main map as well.
Tested both using SRAM Plus and the mini SRAM saving feature in the retry patch.
I got what I think is an issue with it: I finished a level with 3 DCs, so I started it again. The DCs I took previously re-appeared.
But when I died, I got back my 3 DCs and they disappeared from the level.
Also if I get a coin, reach midway, and then start select out of the level (if I have retry and start select is the only way out because automatic prompt), I come back and start at midway, but without the coin.