There's an option to fast-sync by downloading a snapshot of the datadir from a synced pruned node.
This involves a stronger trust assumption compared to the proposed
assumeutxo (as well as of
assumevalid) as you're giving away full control over your datadir. This may potentially open your node up to certain types of attacks - for example, a buffer overflow may be found that affects reading (expected to be previously verified) blocks from disk, but not when reading them from the P2P network. Or feeding your node with inconsistent database state that triggers some unexpected edge-case.
I'm aware of two distributors that publish pruned datadir snapshots:
- prunednode.today, which is maintained by the Specter wallet developers and integrated into Specter
- BTCPay's fastsync, also integrated as an option into BTCPay. Instructions for downloading the snapshots are available here.
However, both of them are for mainnet. I'm not aware of testnet snapshot being available anywhere.
Using a snapshot could also be a good option if you already have a synced node and want to setup a new one on a new machine.
In a project I'm working on, I integrated prunednode.today as a way to quickly setup a pruned node (+block explorer, electrum server and more). This one-liner gets everything up and running:
docker run -it --rm --name ez -v ~/eznode:/data eznode/eznode TRUSTED_FASTSYNC=1
More information available at https://ezno.de/packages#fast-sync