I commend Peter for showing the complete development and construction in his videos. Few companies would demonstrate such transparency. They show the mistakes and triumphs and deserve much credit for this IMO.
We should wait and see when he's done if the engine and airframe work as originally envisioned. Peter seems like the type of chap who'll admit any shortfalls with the finished product as he's demonstrated so far to date.
He's not an engine guy but he is a determined, talented and tireless engineer.
My advice to anyone considering any alternative engine is to wait until at least one example has shown excellent reliability for at least 100 hard ground test hours (at MCP) and 500 flight hours. This Audi based engine is nowhere near that benchmark yet.