The businessman built the court, skate bowl and two-storey double garage on the site, which is in an Area of Outstanding Natural Beauty, without planning permission in 2016.
He has been locked in an ongoing battle to save the development after South Hams District Council ordered him to tear it down and return the land to its previous condition.
His last planning application was turned down by the council in September 2019 because “the development represents an unwelcome and incongruous intrusion into an undeveloped countryside location”.
Mr Thomas’ latest plans include “substantial new planting of over 1,000 native trees” to “help screen” the development.
They also propose to build a bat roost and nest boxes for swallows and sparrows, plant wild flowers along the fringe of the estuary, and clear reeds and silt from a nearby wetland area.
Mr Thomas has also said he will paint the roof of the garage a darker grey colour to address “previously stated concerns that the existing, light-coloured roof prevented the building from assimilating more successfully into the wider landscape”.
Plans for the original house itself had to be scaled back after they were first submitted in 2011 and were not approved until the following year.
South Hams Society has urged people to write to the council about the planning application.
The conservation charity wrote on Facebook: “We at the SHS aren’t against people doing what they want with their homes: but we are here to protect the AONB for everyone to enjoy.
“The South Hams Society works hard on behalf of the community to keep the South Hams special, to monitor inappropriate development and to insist that SHDC enforces their own stated planning policy when necessary. Otherwise what’s the point of having it at all?”
The Independent has approached Mr Thomas for comment.