rom flashing – Is a device with a custom ROM but without TWRP measurably safer than one with a custom recovery?

Is a device running GrapheneOS or a custom ROM in general, without a custom recovery (such as TWRP) installed measurably more secure than one with a permanently installed custom recovery?

From a security perspective, is it sufficient to use TWRP only temporarily (e.g., for backups or flashing) and then relock the bootloader, or is it preferable to completely avoid installing a custom recovery?

I am aware that GrapheneOS can be installed and used without TWRP, and I am interested in understanding whether the same security considerations apply to custom ROMs in general.