Early Jan 2025 the 20 min reset should be removed and Testnet won't have this issue any further.  Full POW is clearly the way, Testnet has pool activity now too, which is far different than back in the day. 

I'll definitely mine with y'all if it is ever open to the public or if you need a tester for some blocks.

Right now, I'm on BTClab.dev, paying a 10% fee.

My blocks include transactions as well:  https://mempool.space/testnet4/block/0000000000000002cedaf2784715288a9b3765e71d2c6c6c4b9c040b092a1e5d