In a September 7 forum update, EIP-8148 author Dmitry Gusakov described revisions that would cap a validator's effective balance at its chosen sweep threshold and allow the threshold to be set during registration. The proposal dates to February; the recent post discusses changes to that draft. Ethereum Magicians; EIP-8148
The current specification covers validators with 0x02 compounding withdrawal credentials. It would let them choose the balance above which funds are swept to their withdrawal address, instead of relying solely on the default 2,048 ETH threshold. Gusakov says existing 0x02 validators would retain a choice if the network later changes its maximum effective balance. EIP-8148; Ethereum Magicians
The official EIP is marked Draft. Its proposed behavior should therefore be distinguished from Ethereum's currently deployed validator rules. EIP-8148
Correction (September 8): An earlier version called EIP-8148 a new proposal and included 0x03 credentials. The article now identifies the recent forum update and the current specification's 0x02 scope.