Pit vipers on Phuket and other tips for Thailand

[Asanoth]

Hello,
we are planning a trip to Thailand (land wildlife) and the Philippines (underwater wildlife) for4 weeks.
We arrive to Phuket on December 25th evening and have 6 full days in the south and/or Bangkok area before moving to Khao Yai for 3 nights and Kaeng Krachan for 4 nights, we fly out on January 8th in the evening. A lot of backtracking is caused by trying to avoid weekends and holidays in national parks.
We are still working on our south itinerary, I was thinking of spending 2 nights in Phuket (1 night for sure after the flight) and move elsewhere after, possibly spend day or two in Bangkok to look for turtles in parks and vipers, retics and preferably also homolopsids. I am new to this and I do not touch subjects as of now.
My main aim in the south would be Phuket, Malay and Wagler Pit Wiper, but honestly, I am happy for any snake I see.
I see to main pit vipers hotspots in Phuket on iNaturalist: east of Khao Phra Theao NP and area around Kathu waterfall.
Do you know, if these areas are accessible (legally) after dark? Or would you have any other recommendations for Phuket and around? I found one topic here recommending a lodge nearby Krabi, but I do not think it would fit well with our diurnal activities. Our other aims would be mammals

I would also very much welcome a recommendation for the tentacled snake in Bangkok, something can be found in iNaturalist, but still, and pretty much any other tips are very much apprecitated. In Kaeng Krachan, I would very much like to spot the Giant Asian Tortoise and a retic (hoping to get one in Baan Naka); there are also water dragons in Khao Yai, but I believe the chance is very low in the dry season.
On the Philippines we only go to Malapascua and Anilao, with one night in Cebu city near the airport and same for Manila T3, so I guess there is not much herping to be done, plus we plan to do as many night (and day) dives as possible.

Thank you for any tips!

PS: I know there are herping tours in Phuket, but for one or two people they are very costly.

[Kyle Barker]

We came out of Phuket with precisely ZERO snakes! What a bummer! The patch of forest east if the airport area seems to be where most are going to find stuff in that crowded island. I suggest renting a car or scooter and bring rain gear for cameras etc. We got hit with rains every single day of our stay haha.

Good luck! Phuket viper is very much on my list to find, hopefully you make out better!