I read your post days ago and didn’t really get it. I guess you are asking if you should start blast and cruise now mostly. I started doing stuff almost 30 years ago…. Always did PCT early on. Then went to “TRT” instead. I don’t know if this is true, but my doctor would make me get off as my wife wanted to keep popping out babies. 3 kids later, always blast (quasi now, I’m old) and cruise. I adjust the cruise to get bloods right (I have to drop less than preference to get bloods right then stay close to baseline). There was some point, where TRT was necessary. But for you, seems like a personal choice, because so young. The smart thing, to me, you are doing is 16 weeks. At least if you PCT right (diet etc) you should have some really good results. One might say try PCT this time and see. Another might say PCT sucks.
Before you go any further get bloods done to determine where your baseline hormone levels are.
If they are shit then TRT might be in your future.
If they are great then personally I would not mess with them as you are still young.
I can only comment on PCT from a personal perspective. On the basis long esters take a few weeks to clear and I used HCG/ Clomid/ Nolvadex for a month (2 week break after last shot before starting HCG) i felt good for the duration of the PCT (5 weeks (7 weeks after last shot). From there it was a decline for about another 6 before it all stabilised. IMO I believe for me a return to baseline (or near) was 5-6 months.
RE fertility, it’s a mixed bag. Some people don’t have issues some do, however there is significant evidence to suggest that AAS use affects both fertility and long term T levels. If fertility is a concern have a sample frozen as insurance.
You should consider using a low dose HCG during your cycle to maintain testicular function and size, it will likely help with both fertility and PCT recovery.
Vigorous Steve has content on you tube covering your questions, he is a good authority on such things, go take a look.