As we discussed in that other thread, I don’t think you can.
For me just monitoring my sleep quality tells me when I am pushing too hard, or drinking too much coffee… 
You could make up some very simple estimate like
Big compound exercise leg day, like squats could be 100, medium could be 50, and short duration isolated smaller muscles 25 TSS. I am just kind of making up these numbers as there are so many variables but just something like this would probably be good enough. If you get super sore legs, back or posterior chain or believe you will be call it 200
Since strength training is anaerobic, I would say compared to aerobic training it’s probably 2X more stress on the body than as similar RPE in cycling. This stuff is all so inaccurate and always will be that you just need to throw some numbers in there to make it give you indicators when you might be doing too much, that usually backs up how you feel, sleep or HRV…