We decided on option 3 in the end, travelling far to Ampah during the 1st night before making our way back slowly. Below is a map showing roughly the route which we took.
We found 7 locations with possibly 2 species of cryptocorynes only, namely C. cf. cordata and C. cf. striolata. We did not have sufficient time to search for C. hudoroi on the last day as we covered too much distance in this trip. It was still within the rainy season and we encountered a heavy rain during the trip which caused many rivers along the way to flood, hampering our search.