Is a DI box necessary to use pedals in studio (without guitars)?

hello. I found only threads for guitarists about this, so I thought to write it down.

I'm recording an album in my small home studio, and I need to use my small pedalboard (5 pedals - Strymon, 2 Meris, UAFX, RedPandaLab) through loopback.

This is the setup:

First of all, I'm not a guitarist, I'm a kyboardist who uses pedals, and in this case the pedals should process tracks from the DAW and coming back into the DAW. I have a RME Fireface 802 FS, outputting a stereo signal (2 line out) into the first pedal (Y cable), and from the last pedal (another Y cable) going out stereo into 2 line in on the RME (on the back). So the signal is coming in at line level and coming out at line level (right?). The length of the cables (from and into the RME) is around 5 or 6 meters. Should I use a DI (or anything else?) after the pedalboard?

Thank you:)