I wouldn't remove the glass and use a wedge. The wedge won't work right with the two mirrors as they absorb some energy, unlike refractor lenses which pass all of it. You need an ERF, be it solar film, etc, on that SCT even if's off axis and partial. Solar film is cheap. It will do the job.
That said, aperture being so similar, your 72mm refractor versus a 3" (75mm) aperture on your SCT, you're just getting the focal ratio as the SCT mirror is actually F2-ish and then amplified. You might as well just be using a long high mag barlow on your refractor to get the same thing, with maybe possibly slightly higher brightness even (due to no obstructions and no mirrors absorbing some transmission, as those mirrors are probably less than 94% reflective by now, maybe in the 80's % range at this point). It's heavier and catches more wind; the refractor is much easier to handle and you can use your wedge as normal. You would just need a 4x barlow maybe to mimic the focal-ratio if you need high mag views.
Edited by MalVeauX, 19 January 2021 - 10:15 AM.