Trailing arm crossmember support Q's

[Sherman Snouts]

Hello, everyone. I decided to cut my crossmember to allow compact exhaust routing. I've read the threads on this procedure, and there seems to be alot of stress about the structural integrity after this modification. I used the method of using a thick wooden board to act as a pilot to hold the saw steady (credit goes to whoever came up with this clever idea). And I see lots of people welding a thick pipe in the hole to support the crossmember. So my concerns are these:

My frame is already painted. I know, I should've researched these mods before going to final paint. But I am concerned about welding splatter and having to touch up the paint.

Is the support really neccessary? I'm sure it would'nt hurt to reinforce the crossmember, but that metal is pretty thick. And the crossmember is pretty stout.

And the real question: Has anyone ever seen one of these crossmember mods fail when no support is added? If so, I'd like to see where the failure point was, if pictures are available.

Thank you in advance! And I will post pictures ASAP.

LWB, static drop, no towing or hauling in mind. 3in hole saw.