You have turned down the HK holster dead end. I have been on that street.
You will need to find a custom kydex maker. I used Gunfighters Inc for an OWB for a USP 45 with a 400 Surefire. They were fine.
I tried squared away holsters and will have to ask Mastercard to refund my money.
I needed a retention holster for a Glock 19 Roland and Safariland makes one. It takes 4 months to get it. And that was before the Vid.
If you need retention, it is going to be even more difficult.
It tells me a lot about a dude when he talks and talks and talks about his HK pistol. Then I ask about the holster. He. Does. Not. Even. Own. One. Which means he has never trained one day with the gun.
I have a T-Rex ragnarok that is pretty good too.