Tren advice: 10 weeks at 400 mgs or 20 weeks of 200mgs?

I've done many cycles in past. Recovery not an issue, I'm 31 and on 200 -300 mgs of self administered TRT. Low bodyfat, do 7-12 25 minute cardio sessions a week, and have a decent diet except for a few meals a week. Lately I've been cruising on 300 mgs of test E. I don't really do heavy cycles anymore and have a few bottles of tren E. I was initially thinking of running 300 mgs of test E and add in 400 mgs of tren E a week for 10 weeks. But was wondering if anyone runs tren for long periods of time out there. I know 20 weeks is really long for tren, but it would just be at 200 mgs a week with 300 mgs of test and nothing else. I don't compete or anything, just looking to stay very lean and add steady muscle. And just want a light, low toxic cycle. Is 20 weeks too long even at low dose? Or just go with my original plan of 300 mgs of test and 400 mgs of tren. Any input would be appreciated.