May I ask what made the scenario unattractive to you?
I'd like to learn from my mistakes
A senario demanding a different grand strategy attracts my interest. This is probably too much for you as many previous SGOTMs were unknown to you. I have participated SGOTMs since SGOTM11 (only skipped SGOTM18). From 11 to 15, plastic ducks had deployed distinct strategies to achieved different goals (UN, Space, conquest, and Religious diplomatic). Both 13 and 14 were conquest victory, while the best victory for 14 should be domination and we adapted different military routes from 13 to achieved the goal. 19 was a better scenario among the last 4 SGOTMs which demanded the balance of research and military, that's the main reason why I came back. For the 1st time, we used Cuis as the major unit, which was an obvious choice for most of other teams, but a unusual choice for our team.
TBH, I don't feel a different grand strategy is needed for SGOTM20, unless the hidden goal might give significant change, while that would be a disaster design. Frederiksberg gave some good reasons why the hidden goal was not a good idea. SGOTMs provide a platform for competition. While RNG is the build-in mechanism in civ, the map designer could still reduce the effect of RNG and unpredictable elements as much as possible, so that the strategies and micromanagement skill could play the major goal in winning. SGOTM12 map has been the best design in this.
- Clear starting area so that no team can gain significant advantage from start due to gambling like in SGOTM16 and 17.
- No barbarian which could cause serious trouble and unbalance among teams.
- All AI were contacted from start so that there's no RNG effect of meeting AIs.
- 1 AI was given Alpha to be fair about tech trade.
OTOH, SGOTM20 are introducing and increasing those unpredictable elements. Besides the hidden goal, the major goal of 70 temples requires a lots of RNG involvement of spreading, which could cause serious effect if a team fails the spread in the last few turns. A few turns could be the determinative for laurels. Moreover, as shakabrade pointed out, the requirements of 2 religions of every owned city could be ignored without liberation limitation. What's the point of prohibiting conquest victory then?
I don't criticize your design as you are neither a senior designer nor a senior SGOTM player. I appreciate your effort and enthusiasm on getting the SGOTM20 up.

As I said already, the scenario itself is not the determinative factor for my participation, a good team to play with is.