I have disabled SIP since the first Mac Os X it appeared. I like to alter some kexts, frameworks, etc . Just you have to know what you are doing and take some basics precautions.Thing is what deeveedee is doing is basically just spreading paranoia and FUD.
His claim is correct in a way that the security will be lowered somewhat, this is simply because it is absolutely impossible to put back the proper drivers into the system or downgrade needed frameworks etc without breaking the seal. Access to the root volume is required for the internal system folders and frameworks to do patching.
A sizeable chunk of the patching is basically adding back drivers from previous OS's that Apple removed and downgrading things, then figuring out how to make them work with the changes on new OS's.
The same goes for SIP but OCLP is actually more intelligent about it and disables it only for the parts that are needed and not entirely, to maintain the best security that is possible while allowing patching.
Also if going by the logic he uses in the claims, OpenCore itself would be equally as bad if not worse since it injects many things directly into memory during boot, like BlueToolFixup for Bluetooth as an example. Root patching only came to be because there was no other way, as some things cannot be injected directly via the bootloader and have to be on disk.
EDIT: Also forgot to mention, the app is entirely open source and the code is readable in Github. As for attestations go, pretty unfeasible for such a small scale open source project especially if they cost money.
Never a single problem.