Totally can relate to those long nights!
In our experience, I don't see that by using timing more so than cues can cause any problems. I often wondered this myself. My DS is 20 mos so there is quite an age difference between mine and yours....but for the last month or so I have been able to ask/tell DS to push out more potty when he's on the potty. I am amazed that he actually does it. Sometimes when I potty him, he just wants to squirt a little out and be done, then I say "Oh....push out some more potty...I know it's in there...go ahead...push out a little more." Then I know that his bladder is really "empty" and we can go a longer stretch before the next potty break. I did not get real cues from DS until around 14 months. As far as amounts....mostly, he would fill just the bottom of the BBLP and sometimes he wouldn't cover the bottom...just about a 1/4 of it. It really did vary depending on how long between potty breaks, fluid intake and if we had misses. Hope that helps a bit.
In our experience, I don't see that by using timing more so than cues can cause any problems. I often wondered this myself. My DS is 20 mos so there is quite an age difference between mine and yours....but for the last month or so I have been able to ask/tell DS to push out more potty when he's on the potty. I am amazed that he actually does it. Sometimes when I potty him, he just wants to squirt a little out and be done, then I say "Oh....push out some more potty...I know it's in there...go ahead...push out a little more." Then I know that his bladder is really "empty" and we can go a longer stretch before the next potty break. I did not get real cues from DS until around 14 months. As far as amounts....mostly, he would fill just the bottom of the BBLP and sometimes he wouldn't cover the bottom...just about a 1/4 of it. It really did vary depending on how long between potty breaks, fluid intake and if we had misses. Hope that helps a bit.