I don’t really have anywhere to do a good 20 min sweet spot workout near me, roads are way too hilly/lumpy and the longest climb I have ready access to is about 16 mins long.
Sooo…as sweet spot workouts are really about accumulated time at sweet spot effort…surely there is nothing wrong with something like the following:
3 blocks of 2 x 10 min sweet spot - descend ( I guess about 2-3 mins ) with about 10 mins rest.
There are similar workouts in the library so I guess it should be ok right?
isnt that antelope?
Antelope is with larger recovery valleys between each set. Antelope +3 is kind of the same but 6x 10 mins with 2.5 min recoveries between each.
My theory is that they are all so similar that it is really the same outcome in a slightly different form?
Antelope +3 is what i was thinking of. I just did that one here recently. . i do 90% of my rides outside and you just have to accommodate the best you can. I think Chad said a few weeks ago if your outside then 90% accuracy is pretty good.
Yesterday the worst part of outside riding happened. i finished my vo2 inverse at the bottom of a 15-18% grade hill 
There is some truth to this, but it is more nuanced than the simple math would imply.
Would you say that 60 x 1 minute at SS (and some recovery time) is the same as 1 x 60 minutes?
If that is a correct observation, whole blocks vs split intervals are likely to feel different at the least, and may lead to different loading on the body (and mind?) at most.
There are times where a short break may be a minimal impact, and others where larger ones will lead to different results.
You have to consider the goal of the workout, not just the final tally of time in zone. As such, these longer SS intervals are about continuous load on the body leading to more fatigue.
If you split those blocks in half with too much break, you are not pushing the body in the same way as the longer block.
There are MANY workouts in the library. Each one servers a particular purpose.
The existence of one similar to you suggestion does not validate it for use in all cases. As mentioned above, workouts with particular intensity, duration and recovery periods are all meant to apply stress to our bodies, that should drive adaptation.
Each one is different in particular ways to push one or more elements of higher power, longer duration, or shorter recovery.
The challenge in this comparison is considering the intent of the workout vs the simple similarities.
I think your suggested mod is a fine workout, but it varies from the intent of the original Hunter criteria.
You are mitigating everything coach Chad discusses in the podcast. I am paraphrasing but he said something along the lines of sweet spot workouts being more than fine as long accumulated time in zone is achieved.
You response seems to go into great length wanting to say ‘its not exactly the workout as layed out in the plan but it is still ok’ while using an (to say the least) extreme comparison. I thank you for pointing out the small nuances and their probably inconsequential impact on anyone not trying to eek out .005% marginal gain.
what plan are you following? At least in sweet spot base, there is a weekly progression to increase time in zone. That is a combination of longer intervals, and reducing time between intervals. Something to consider.
Personally when I climb they tend to be 30 minutes or longer, so I like to take sweet spot intervals out to 30 or 40 or 50 minutes. But I’ve got a 50 minute stretch of flat road into a headwind, so its a lot easier for me to dial-in the length of each interval.