We currently have drips running (a ram eater)
While I am not sure how you calculate the payouts of the drips, doing the actual drip transfers you might have use for what I use to pay out our daily staking rewards to ALIVE stakeholders, and that is over 9k transfers every day, and I send 25 transfers in each custom json transaction, and it takes about 45 minutes to do all of them.
The way it works is I have a 0.5 GB VPS from Privex running Debian 11 with IPv6 only and IPv4 out through NAT from Privex costing $2 USD per month, and it runs both the payouts and also our tipping bot as well, the tipping bot takes about 45 MB in ram, I have not measured the payouts for ram but I have never had any issues with it.
https://github.com/flaxz/alivepay
I have 2 smaller scripts there to calculate the payouts which saves them as CSV files, and then the bigger script payout.py which loads those files into a sqlite3 database, and then runs the payouts until they are finished, with failover and recover all built in, I made the first version myself, but also hired bambukah and captaincryptic to add the more advanced stuff.
Below is also our tipping bot as well, it's a fork of the original pizza bot, all is open source.
https://github.com/flaxz/alivebot
!ALIVE