I'd scan file with VirusTotal, or alternatives

Developer preview license keys are expired

I just offer an alternative, how to make it with Python

Python

ClassMethod IsValid(w As %String) As %Boolean [ Language = python ]
{
import re;p=r'\([^()]*\)'
while re.search(p,w):w=re.sub(p,'',w)
return len(w)==0
}

While my global is quite simple, and it's size is about 1.1 GB, or around 18 bytes per record

USER>do ##class(%GlobalEdit).GetGlobalSize("/usr/irissys/mgr/user","YYY",.all,.used)

USER>zw all
all=1109

USER>w all*1024*1024/65000000
17.89031975384615385

After restarting, with a cold cache, I got 17 seconds

USER>s sub="", count = 0, ts = $zh for { set sub = $Order(^YYY(sub)) quit:sub=""  set count = count + 1 } write !,"elapsed: ", $zh-ts 

elapsed: 16.994676

So, my disk can read around 65MB per sec

If your enterprise still uses mechanical disks, that's still a factor that has to be considered

All the blocks required to be read to get through the list can be placed all around the disk/s. And it takes time. On a live system, with many changes, and when a lot of different data is stored, the next block can be far from the previous one. So, on mechanical discs, defragmentation is matter, and may slow the speed.

I don't know the character of your data, but if you have a lot of data, stored in the globals, it will require to read much more blocks, to even just count the items.

And most probably the easiest way to solve it, is just to use bitmap index.

If you wish to have a conditional filter, then you can use it this way

SELECT * FROM SomeTable
WHERE (:FilterName   = '' OR Name   LIKE :FilterName)
  AND (:FilterValue1 = '' OR Value1 LIKE :FilterValue1)
  AND (:FilterValue2 = '' OR Value2 LIKE :FilterValue2)

As I mentioned above, it's a complicated question, and to be sure what's really happening, and why the speed is so slow, it requires a look deeply into the database file and into hardware.

There is an interactive course about using IRIS REST and Angular, which you can try here, right from the browser, git it a try

What is the actual concern, then?

From my experience on different systems with highload, I did not see effects, that could point to think about it. 

Python may help

Class dc.Demo
{

ClassMethod ValidateJSON(data As %String = "") As %Status [ Language = python ]
{
import iris
import json
from json import JSONDecodeError

try:
    json.loads(data)
    return iris.system.Status.OK()
except JSONDecodeError as ex:
    return iris.system.Status.Error(5001, f"{ex.msg}: line {ex.lineno} column {ex.colno} (char {ex.pos})")
except Exception as ex:
    return iris.system.Status.Error(5001, repr(ex))
}

}

And result

USER>set status = ##class(dc.Demo).ValidateJSON("{""aa"":123 ""name"": ""value""}") do:'status $system.OBJ.DisplayError(status) 
ERROR #5001: Expecting ',' delimiter: line 1 column 11 (char 10)

USER>set status = ##class(dc.Demo).ValidateJSON("{""aa"": true, ") do:'status $system.OBJ.DisplayError(status) 
ERROR #5001: Expecting property name enclosed in double quotes: line 1 column 14 (char 13)

USER>set status = ##class(dc.Demo).ValidateJSON("{""aa"": wrong ") do:'status $system.OBJ.DisplayError(status) 
ERROR #5001: Expecting value: line 1 column 8 (char 7)

USER>set status = ##class(dc.Demo).ValidateJSON("{""aa"": true}") do:'status $system.OBJ.DisplayError(status)

try this

set objectContext = ##class(Some.Class).%OpenId(123)
write ##class(Ens.Rule.Definition).EvaluateRules("Rule.ClassName",,objectContext)

The error on screen shot saying Access Denied, why do you think it's Timeout?

Check the amount of connection available for you, and how much connection you do

Not so much magic in it, if you already know how to read it, the content of XData is just a Stream, which can be used both ways. Just Write to it, and %Save it. And you will probably need to compile the class

Class Demo.Test
{

XData OpenAPI [ MimeType = application/json ]
{
}

ClassMethod Update()
{
    set xdata = ##class(%Dictionary.XDataDefinition).IDKEYOpen($ClassName(), "OpenAPI")
    do xdata.Data.Write("{}")
    do xdata.%Save()
}

}

In VSCode, the content of XData will not appear after that, because it happened on the server, and VSCode will not see the changes, you'll need to export it manually

@John Bradshaw Converted from comment to a separate question, please update the zversion which you using 

my tool irissqlci supports CTE (except recursive). As well as SQLAlchemy with SQLAlchemy-IRIS

You can read journal files from any instance, but using Journals API, not using management portal