with in 200us/DIV the 1Mpoint was never available, same for 2Mpoint, it is disabled while in 400us/DIV.
Call this bug if you wish, but it is by design like that (this is not that we can't "patch" the firmware to remove these restrictions,
but note that the FPGA will not sample anything when such illegal selection has been chosed, see picture - no signal but freq
counter is counting - here square - 1khz signal).
Btw, i recall i thought they tried to implement it, but i was wrong:
First of all the 200us/div and 1M was not working from the beginning. Right after i recognized it on a very
first firmware i send it as bug report - i don't know when exactly but one on next firmwares was able
to enable 1M in 200us/div but zoom was not working. So i asked again and got answer
that the way how the DSO is designed they can't enable 200us/DIV and 1M - the next fw version then was
not capable again of doing 200us/div and 1M. I thought, what a bummer, but anyway,
it works below and above 200us/div, or just with 512k while in 200us/div.
I've checked right now again this old fw, and honestly zoom was another bug with no relation to memory depth.
There is possible to seelect 1M in 200us/DIV, but the firmware is still using 512k, so no i correct myself, 1M and 200us/DIV
it was never really possible.
In my eyes, it was design decision, exact like e.g. in dual window mode no option to remove menu. Is it not possible?
For sure it is, but they chosed to not allow it and we have to accept it.