notification engine is slow and causes main UI thread to be blocked

Describe the bug

notification engine is slow and causes main UI thread to be blocked.
I have many org files with 1000+ lines, and when notifications are enabled, the UI will periodically freeze when fetching notifications

checkhealth

==============================================================================
orgmode: ✅

Orgmode ~

• ✅ OK Tree-sitter grammar is installed, but not by nvim-orgmode plugin. Any issues or version mismatch will need to be handled manually.
  If you want nvim-orgmode to manage the parser installation (recommended), remove the installed parser at "nil" and restart Neovim.
• ✅ OK Setup called
• ✅ OK org_agenda_files configured
• ✅ OK org_default_notes_file configured

Steps to reproduce

Have 30+ org files with 1000+ lines of scheduled headers in each.

Expected behavior

UI does not freeze

Emacs functionality

No response

Minimal init.lua

local tmp_dir = vim.env.TMPDIR or vim.env.TMP or vim.env.TEMP or '/tmp'
local nvim_root = tmp_dir .. '/nvim_orgmode'
local lazy_root = nvim_root .. '/lazy'
local lazypath = lazy_root .. '/lazy.nvim'

for _, name in ipairs({ 'config', 'data', 'state', 'cache' }) do
  vim.env[('XDG_%s_HOME'):format(name:upper())] = nvim_root .. '/' .. name
end

-- Install lazy.nvim if not already installed
if not vim.uv.fs_stat(lazypath) then
  vim.fn.system({
    'git',
    'clone',
    '--filter=blob:none',
    'https://github.com/folke/lazy.nvim.git',
    '--branch=stable', -- latest stable release
    lazypath,
  })
end
vim.opt.rtp:prepend(lazypath)

require('lazy').setup({
  {
    'nvim-orgmode/orgmode',
    event = 'VeryLazy',
    ft = { 'org' },
    config = function()
      require('orgmode').setup(
        { 
          notifications = {
            enabled = true
          }
        }
      )
    end,
  },
}, {
  root = lazy_root,
  lockfile = nvim_root .. '/lazy.json',
  install = {
    missing = false,
  },
})

require('lazy').sync({
  wait = true,
  show = false,
})

Screenshots and recordings

No response

nvim-orgmode version

2fc30d36fd1c3e6086a7424858e19a52a29ae937

OS / Distro

NixOS

Neovim version/commit

0.11.6

Additional context

Here is my nixvim setup that I used to test functionality. https://github.com/dtvillafana/nixvim

Reproduce the freeze using the provided minimal init.lua with 30+ large org files and notifications enabled, then profile notification fetching to identify the blocking work. Done means the same workload no longer periodically freezes the Neovim UI.