...
BLOB1{Bead}|PEPTIDE1{A.G.T}$BLOB1,PEPTIDE1,1:?-?:?$$$V2.0
Brackets
You can't have CHEMs or BLOBs inside brackets.
If you only have the CHEM or BLOB inside the bracket, you don't know how it is connected to itself.
If it is connected to anything else then you have more than one simple polymer. You cannot define repeating groups across multiple simple polymers.
Summary
Blobs and CHEM{*} behave in a similar way, but they are used in different contexts. The project is interested in extending the blob name vocabulary, so please let us know if you have any suggestions.
...