With Writer 5.3.6.1 a performance issue was introduces (new to 5.2): When 1 ore more text boxes with some text are present on a page, the performance of test inserting / editing goes down very notably. I see this on every page template with text frames I use. It is especially easy to see if a text inserting tool like AutoHotKey is used. On a blank page, inserting some lines of text takes less than 1 second. With a text frame on the page, inserting the same text takes several seconds.
I use the German version.
Install 5.3.7.2 and retest. https://downloadarchive.documentfoundation.org/libreoffice/old/5.3.7.2/win/
with 5.3.7.2 I can confirm it's much faster. Still not as fast as with a blank page, but now it's usable again. Thank you!
OK, expected. Resolved now for the final 5.3 build. Keep an eye out in 5.4 or 6.0 for recurrence as we continue to rework the DirectWrite Direct2D font rendering. https://cgit.freedesktop.org/libreoffice/core/commit/?id=5440837e02dee8bc884e02be697bfd4def621d26&h=libreoffice-5-3