I',m in favor of leaving Ramree 'as is', because I think it functions in line with what I think was possible as borne out by what was done.
BUT:
If you do want to change Ramree's influence on Burma, understand that the supply cap at Ramree is not the issue, because DBB 28-C from ~December 2011 already has a very restrictive supply cap at Ramree! In my current game Ramree is built to 3-port, 7-airfield, 1-fortifications and can receive (via land) only 550 supply
one time per week from Akyab.
The way that Ramree influences Burma is that (troops and) supply are brought into Ramree by sea and then move inland, which is the reference (the link) that Jeff made.
As far as supply goes, the key to modifying supply moving from Ramree into Burma is Prome. In DBB 28-C ~December 2011 there is no supply cap at Prome. In spite of that, the supply path is made much greater by the need to jump the jungle hex to get to the road. The supply path is 'medium range', (in fact it is just inside of being long range). Supply path from Ramree to any other base in Burma is long range (and of course most bases are completely out of range).
Ramree itself is a very poor port and requires lots of building, starting value being 0(0).
Conclusion: IMO Ramree is fine as is. DBB already put in place a very appropriate supply cap and no further adjustments are needed. If you must reduce Ramree's influence, adjust the supply cap at Prome.
This is the (partial) quote from a developer that I am using for the ranges. You start with 100 and subtract the supply cost for each hex.
Short range is trace value of 89 - 100 and is used 4 times per week.
Medium range is trace value 49 - 100 and is used 2 times per week.
Long range is trace value 10 - 100 and is used 1 time per week.
(JWE: I know you know this stuff but I included extra for others.)