The BTCR playground currently uses testnet which can be difficult to work with due to inconsistent block generation, large re-orgs and availability of coins. The btcr playground would benefit from a more controlled network to provide a better user experience.
There is a proposal for a more developer friendly network signet that aims to address the issues with testnet by centralising block creation and providing scripts to request coins from a central faucet. A bitcoind fork has been provided by kallewoof which can be used to connect to the signet chain. It is also possible to start a bespoke signet chain if control over block production rate is desired.
One of the benefits of this is that the chain is very small (at the moment) and so syncing times for the chain are negligible, as is the amount of resources required for a node which could happily be deployed as a part of the playground environment.
On the downside, there isn’t support for signet in the standard libraries (bitcoinjs-lib) and so some work would be required to fork and maintain those. There is also the risk that the proposal doesn’t get merged into core and the network discontinues, requiring rework.
An alternative to both testnet and signet could be to set up a regtest environment and scripts to run a similar local network managed entirely by the playground.