Sorry, just got this. Forgive the late response.
But you should actually be able to run both the "blue" and "red" settings during flower with zero problems. In fact, the light spectrum on blurple lights is one positive benefit that they have over HID lights.
Run all 3 of your lights and run them with both the "veg" and "flower" buttons on, as the plants will be able to make use of both spectrums in flower. It's mainly in veg that you only want blue light and no red light, but in flower the plants will be able to make use of both red and blue light. With blurple lights, you want the blue setting on during veg. Then during flower you'll actually want both red and blue on. That's the tl;dr version of it.
I'll elaborate more on it below but you don't have to read it if you don't want to. It's pretty much just me explaining why I'm not talking out of my ass, but all you really need to know is that you definitely should use both red/blue settings on the blurple light when you're in flower! It will provide you with all the light you need, as well as all the spectrum you need too!
MH/CMH lights are blue spectrum light, and HPS lights are red spectrum light. You can veg with HPS and flower with MH, it will work it just won't be optimal. This is because plants use the blue spectrums of light for veg growth, and red spectrums for flower.
The red/blue thing comes from the limitations of indoor lights. Plants are definitely not restricted to just blue/red light though as the sun has a WIDE variety of light spectrum similar to that of a rainbow; red, orange, yellow, green, blue, indigo, violet/ultraviolet. Plants can and will make use of every last part of the light spectrum. The problem is that most indoor lights cannot cover the entire light spectrum like the sun can, the only lights capable of doing this are Cree/COB LED lights. Blurple lights actually have a wider spectrum than HID lights, but the issue with the blurples is that they aren't very powerful lights despite having an amazing spectrum.
Plants actually operate in terms of light spectrum and not wattage, this is exactly why people are moving away from HID lights. Double ended bulbs and Ceramic bulbs definitely have better light spectrums than Single ended bulbs, however they still don't compare to LEDs. HID lights are a single light source, LEDs are multiple smaller light sources. With HID lights, you're stuck with whatever spectrum it has. However with LED lights, you can get different colored LEDs to mimic a more diverse spectrum than any HID can provide. While Cree/COBs have come down quite a bit in price, they still cost a rather pretty penny.
Allow me to compare a 1000w HPS light with that of your blurple light to give an idea of light spectrum, as before we only discussed light intensity but not light spectrum.
1000w HPS light is 1000 watts, right? However, the 1000 watts of light isn't all usable light for plants. Due to the mediocre light spectrums of an HPS/HID light, your plant is actually only able to use ~300-400w of that 1000w light. Since the plant can only absorb 300-400w of that 1000w light, the remaining 600w of light remains in the form of heat that is totally unusable to your plants since it isn't in the right spectrum.
Your blurple light though, it may only be 130w of light.. however nearly all of that 130w of light is usable because all 130w of light is in a spectrum that the plant can use.
This is why Cree/COBs destroy HID lights with less wattage. The reason a 500w COB set up will outperform a 1000w HPS light is because the plants can use all 500w of the COB, but only ~300w of the 1000w HPS because of the difference in light spectrums of the two sources of light.
Hope that was useful. If you do your own research on light spectrum and how plants react to it you'll come across much better information/explanations than I'm capable of.
All that being said, try not to overthink things too much. It's technically a weed, so it will grow in even the most adverse of conditions. It just won't grow optimally, but it will grow! Optimal growth takes time and experience, but it is something that anyone can do with proper dedication and work. Don't ever listen to someone that tries to make growing plants seem "impossible", as that's total bullshit.
I'm not the best, but feel free to ask what you need to and I'll help to the best of my ability.
