MegaMek opened at 800x600 inside the browser viewport with the unit display, minimap and report pane all floating. Fixed via a seeded preferences file, no patch. Fullscreen without hardcoding a resolution: AbstractClientGUI.initializeFrame() honours a stored window size, and UIUtil.updateWindowBounds() then clamps it to the union of screen device bounds. Under Webswing the "screen" is the browser viewport, so an absurdly large stored size collapses to exactly the viewport at 0,0 - correct at any browser size. Docking: UnitDisplayLocation and MiniReportLocation are 0 = floating dialog, 1 = docked into the main split pane (ClientGUI.setUnitDisplayLocation). Both set to 1. Also turned off the keybinds overlay to reclaim map area (Ctrl+K toggles it) and moved the minimap clear of the left panel. MegaMek rewrites clientsettings.xml on exit, so start.sh re-seeds it from a template every launch, the same way it materialises webswing.config. Verified by screenshot in a live session: frame fills the viewport, unit display is a docked full-height left panel, title and menu bars are visible, map area is substantially larger, and the glyph fixes still hold. Two gaps recorded in TODO. The minimap has no location preference and is dialog-only, so docking it needs a MegaMek patch. The mini report is configured to dock but only appears in report phases, which a headless run cannot reach - no shipped scenario pre-places units, so deployment always blocks - and is therefore verified by code path only. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>