Figured. Fighting games aren't meant to be played on a keyboard. I don't code/design things with a keyboard in mind either. Since it's something I would never use in this instance, I'm afraid I can't really be bothered to make accommodations for keyboard users. Because not only do I not use a keyboard, but it will mess with the inputs timings for controller/arcade stick users. Which is what it's geared towards.
However, I will give you some suggestions, and if you follow them correctly, you should be able to tailor it to fit for a keyboard. The main thing you can edit, is in the tinybuffering.txt, located in the "Coding" folder:
1.) Scroll to near the bottom of tinybuffering and look for this specific(exact) block of code:
[State 10371, SGS Init]
type = VarSet
trigger1 = p2dist X >= 0 && command = "SGS"
trigger2 = p2dist X < 0 && command = "RSGS"
var(43) = 8
^This controls the window allowance for Juli's DCD.
2.) Where it says "var(43) = 8" is what you want to edit. Only the equals value of var(43), which is currently 8. This gives a frame allowance of 8 to perform the move. TBH, for a controller/arcade stick, I still personally feel this is too much, but I digress. You want to increase this value to allow more frames(time) to perform it.
3.) You don't want the value to be too high, because it will make it too easy to perform. While at the same time possibly making the move come out, when you don't want it to. You can increase the value by 1, save it, then try it until you can do it. Or, you can just try set values I would do if I were to change it. Personally I wouldn't go above 13. So you can try 10, and if that still doesn't work, try 12, etc. I'm sure you get the idea by now.
You could also try increasing the CMD time for them both. SGS and RSGS both have a time currently of 24. Essentially 6 ticks for each button. You could try the original 32 time I used to use(8 ticks per button), if you feel so inclined. In combination with the tinybuffer edit. Though I don't think that will be necessary, but it is an option. Up to you.