Change the Old style of using stocks and natives for working with datapackets, to the new with using methodmaps.

methodmap DataPack < Handle
{
public DataPack() = CreateDataPack;
public WriteCell() = WritePackCell;
public WriteFloat() = WritePackFloat;
public WriteString() = WritePackString;
public WriteFunction() = WritePackFunction;
public ReadCell() = ReadPackCell;
public ReadFloat() = ReadPackFloat;
public ReadString() = ReadPackString;
public ReadFunction() = ReadPackFunction;
public Reset() = ResetPack;
public IsReadable() = IsPackReadable;

property int Position {
    public get() = GetPackPosition;
    public set() = SetPackPosition;
}

};

change all function definitions from old syntax with functag and funcenum to the new transitional syntax with typedef and typeset

Change the return type to the new declaration void if there is no type to return at all.

Necessary?

Update all Sendmessages to support Protobuff and with that csgo.
Keep attention to perhaps improve the Sendmessage call with new MessageId rather than using the id string.

replace the old functag and funcenum of the includes to the new declaration style
with typedef.

functag public Action:SrvCmd(args);
becomes to
typedef SrvCmd = function Action (int args);

Take an eye of the funcenum. Is there an direct "typedefenum" or something? Look into standart includes.

Replace old dbi fetch calls with the new methodmap syntax.

Rewrite the base to use plain obb style?
Low Priority issue.

Adding a routine to detect which gamemod is running to change behaviour with sendmessages and somemore else.

Update AC_PrintToChat(All) to support Protobuff and with that, compatibility with cs:go.

Change old variable declaration like:

new Float:x = 5.0;
new y = 7;

to

float x = 5.0;
int y = 7;

It goes:
Float = float
bool - No Change
_ = no tag = int
String = char

Change every Tagging cast like:
float x = Float:array.Get(i);
to:
float y = view_as(array.Get(i));

the code for dicing invisibility is not working in cs:go so write a replacement or at least a workaround like
if (csgo) { return false; }