It is not about stamina I'm scared somehow facing the "real" state of me.
My technique still has issues but it is getting decent so is my feel for water (I would actually put it higher than that it is the main driver in my five strokes) I think I could pull decent-ish times. The thing I know I'm held up till my body health issues improves (if they do or it is unclear to which extend I can fix things).
I know ther is still room for technique improvement, more flexibility and smooth efficient movements but I also know that if I'm not that happ with the measurement there won't be much I will be able to do about it as I can't really go all out while ingraining the proper "correctness" into my body. Going all out means futhering my issues and imbalances (I don't speak of stroke but spine, tensions, etc..)
Overall I think I'm a little too crazy about it and that it would be much easier on me to do it causualy with a friend. I'm a little scare that the me facing me though cloking would bring negativity into my happy introverted swimming bubble :)
PS I'm lucky to have a 50m pool around I often do fast 25m then recovering 25m till the turn starting over again, etc. ;)