Work arounds are identical to options except that they should be used only when necessary. Their purpose is to try to hide problems with various software (not just engines). The default value is always correct for bug-free software.
These workarounds are unlikely to be used or meaningful for GNU Chess.
The default value of 2 corresponds to UCI+. Use 1 to select plain UCI for engines that have problems with UCI+.
The adapter now conforms to the documented UCI behaviour: the engine will be allowed to ponder only if it (the engine) declares the Ponder UCI option. However some engines which can actually ponder do not declare the option. This work around lets The adapter know that they can ponder.
When a ponder miss occurs, the adapter interrupts the engine and immediately launches a new search. While there should be no problem with this, some engines seem confused and corrupt their search board. SyncStop forces the adapter to wait for the (now useless) ponder search to finish before launching the new search.
Some engines do not specify a promotion piece, e.g. they send "e7e8" instead of the correct "e7e8q". This work around enables the incorrect form (and of course promotes into a queen).