The latest beta is v7.61.961 and can be downloaded from here. It includes the following changes:

Beta v7.61.961 changes:
1.Item 22,
2.Item 23, added.
3.Item 24, added.
4.Item 25, optimized.

Beta v7.61.817 changes:
1.Item 15,
2.Item 17,
3.Item 18,
4.Item 19, fixed.
5.Item 20, fixed.
6.Item 21, added. This fix only applies when permonitorv2 is set in
the manifest, which it is not currently. It works by hiding the
caption whenever an MDI window is maximized. Unfortunately, there are
still display glitches which seem to be core Windows 10 MDI bugs.

Beta v7.61.439 changes:
1.Item 13,
2.Item 15, added. Needs testing to ensure $comval() is working as
before and with new feature.
3.Removed support for "Open in new browser" and "Activate new window"
from Catcher dialog as these methods are no longer recognized by
modern web browsers.
4.Item 16,

Beta v7.61.367 changes:
1.Item 11,
2.Item 10, updated.
3.Item 12, added.
4.Item 13, changed.
5.Item 14, updated.
6.Item 3,
Decreased frequency of polling.

Beta v7.61.159 changes:
1.Item 1,
Required significant changes to code.
2.Item 2,
3.Item 3,
Experimental. Required significant changes to code. Uses undocumented
Windows APIs. Only works on Windows 7 onwards. If any part of the
method fails, defaults to global Control+Break.
4.Item 4, updated.
5.Item 5, updated.
6.Item 6,
7.Item 7,
8.Item 8 and 9,
Required important changes to the regex and these identifiers,
so need testing to ensure changes are working correctly and are
backward compatible.
9.Item 10, updated.

1.Changed how on KEYUP/KEYDOWN are processed. This affects the values
returned in $keyval and $keychar for combined key presses.
2.Reverted change to $cnick() so that it returns default values for
non-existent nicks.
3.Changed how Control+Break key is handled so that it only works when
mIRC is the active application.
4.Updated PCRE regex library to v8.44.
5.Updated LibZip library to v1.6.1.
6.Added $width() and $height() sixth $true/$false parameter to enable
custom window-specific measurement.
7.Added support for irc hotlinks that uses the non-standard plus sign
prefixed port number format, such as +6697.
8.Extended $bfind() to support regex searches using:

$bfind(&binvar, N, M, [name]).regex

Where M is a regular expression when .regex is used. The name
parameter is the $regml() name.

9.Extended $regml()/$regmlex() to save result to a &binvar using:

$regml([name], n, [&binvar])
$regmlex([name], m, n, [&binvar])

When saving to a &binvar, returns length of saved text.

10.Updated OpenSSL library to v1.1.1f.
11.Changed [ssl] certificate warning item name in mirc.ini to ensure
one-time reset to a new default value.
12.Added CAP support for setname. This is automatically enabled if
available and will cause the server to send the setname event to the
client when users change their full name. Events are not shown but
are triggered as RAW events.
13.Changed IRCv3 CAP support of draft/label and draft/labeled-response
to label and labeled-response. ACK replies from the server are not
shown but are triggered as RAW events.
14.Updated colors dialog, control+K dialog, and /color command to
support color indexes 16 to 98.
15.Added $comval() .result property to support &binvar as a fourth
parameter, same as $com(), to store one dimensional array results. If
array is BSTR, it is stored using null bytes as separators.
16.Added on CHAR event that returns translated keyboard presses. Uses
the same format as on KEYDOWN/KEYUP.
17.Fixed tray tip display bug with different DPI settings.
18.Fixed /hmake not allowing maximum prime value for table size during a
hash table rename.
19.Fixed display of channel name in numeric 477 on some networks.
20.Fixed script editor rich editbox bug that may have caused font to be
set incorrectly.
21.Added workaround for maximized MDI window caption bug in Windows 10
on monitors with some DPI/resolution combinations.
22.Fixed custom window treebar folder not staying open in some contexts.
23.Added $min()/$max() identifiers that return minimum/maximum of a
list of values. Defaults to numbers. Properties: .text, .textcs,
and .nick. If a single parameter is used, it is treated as a space-
delimited list of values. If two or more parameters are used, each is
treated as a separate value.
24.Added check for numeric 696 on ircds that report errors when mode
requests include more modes than parameters.
25.Optimized processing of long strings in /commands, token identifiers,
$calc(), $eval(), and identifier parameters.