The sidechain ledgers are merged into the bitcoin ledger through the 2-way pegging process, which creates a single merged ledger. Merged means one ledger
I think a lot of side chains will be seen as services beyond the main chain.
These are consistent statements. There is a single ledger of separate services.
Also, in your example, how does 1:1 convertibility between
sidethread 1.0 and 2.0 work, because without that they are
alt threads and are thus inflationary.
I still see the main chain as the master chain being Bitcoin blockchain, and the side chain as being pegged and validated. even though the side chain is criptograficaly pegged so the 2 chains can be reconciled they are separate chains running on separate servers in separate locations a single merged ledger as you put it will never exist, it can only be constructed through a reconciliation proses.
the inconsistency i found funny was actual the claim that "These are separate threads".