After adding 50g lye to 750ml water, then 50g mhrb to both, my mixture, in the recommended qt jar is appx 800ml. Obviously in the qt jar,I'd 'have room' for 50 ml pulls, but it'll be very near the top.

After sitting in this heat bath for an hr - in about 30mins time - should I dump contents of qt jar into 1500ml jar? Or should this be avoided?

Anyone? Just really need a Y or N, from experience, as I have none...ty!

As long as there is room to slosh it around, you should be good.
If there's not much air space, and you can't get an appropriate sized jar, just do smaller pulls.
It will still work fine, but may take more pulls to get all the magic out.

I had the size it called for, just looked a bit small. I had a 2000ml, but thought that might cause problems being too large.

But all is well. Made 4 pulls of 50. I pooled them & now I've got that evaping til morning when hopefully it gets cloudy upon agitating.

I put a 5th pull in the jar and put it in my garage, which right now is about 100f.

So everything went well, using a baster was terrible though, I did almost every pull with pipette.

In the a.m. I'm gonna pop it in the freezer if enough has
evaporated.

Thx for all the help, very much appreciated.

Extraction update:

3.5 hrs evaporating 200ml. About half has evaporated, leaving a white ripling river (fan) with white deposits beneath the solvent. What beauty! <3 MeThinks my 1st extraction is going well.

I believe it's saturated enough for FP, but I'm gna give it a while longer...