I had a similar problem many years ago only one of my break lines was tangled and knotted due to a very near horse shoe malfunction (long story). I wasn't all that experienced and I just remembered my training "can I steer it? Can I land it?" I tried to use rear risers but didn't have the strength so, without hesitation I chopped.
No-one said anything negative to me that day but someone did the following week, who hadn't even been on the dz that day. They said that they'd heard I'd chopped a perfectly good canopy. I just brushed it off as I was confident in my decisions but did wonder how this person felt qualified to question me as they'd previously rode a malfunctioning main down to 1000ft before chopping!
It's your life on the line, no-one else's. If you think there's the slightest chance you can't land your main safely then cut away. It's irrelevant what others would do.