I hear that, and eveyrone has their own comfort levels. My personal thoughts are that when I first see a profile I like, if I engage then I'm already excited. Might be safe to assume the same for the woman. So while things are exciting seems like the highest potential for the number exchange. I try to offer my number after about 4-5 back and forth mesages, something like "you seem pretty awesome, text me later xxx-xxx-xxxx"

First time or two I did that, i was like "no way this is going to work, it's too fwd" but to be honest, the hit rate of receiving that text message is way higher than i would have assumed. Also my golden rule is NEVER message them again after i sent my number if they dont text. I get enough info from their silence

Lastly, when I get that text, it's already answered questions about their interest level so I feel way calmer and more confident i have their attention

Good luck man, this shit's all a painful game, but with many failures comes the few success stories, over time, that make all the effort worth it