We believe a Monero sidechain employing sapling without a transparent pool, with one-way deposits from the Monero main chain onto the (possibly untrustworthy!) sapling sidechain would provide Monero users the nice ability of being able to rely upon the untraceability of Monero RingCT to prevent the sort of traceability analyses seen in Zcash seen here, here, and here without running the risk associated with using an untrustworthy zcash trusted set-up causing a "minting money out of thin air" problem on the main Monero chain.
We believe a Monero sidechain employing sapling without a transparent pool, with one-way deposits from the Monero main chain onto the (possibly untrustworthy!) sapling sidechain would provide Monero users the nice ability of being able to rely upon the untraceability of Monero RingCT to prevent the sort of traceability analyses seen in Zcash seen here, here, and here without running the risk associated with using an untrustworthy zcash trusted set-up causing a "minting money out of thin air" problem on the main Monero chain.