Dungeon Fantasy Houserule

Fixing a Perceived Problem or Expressing My Preference
Dungeon Fantasy is powered by GURPS as it says on the cover, but it is a cut-down specific subset of the entire GURPS 4th Edition rules. GURPS in all its editions and even its older cousin, The Fantasy Trip, is known for offering referees and players a detailed tactical combat system. I have run GURPS (and The Fantasy Trip) without the usual hex map and counters/figures and I think it works fine using only the "theater of the mind" approach. However, a more detailed and tactical combat system using the hex map tactical display may be one of the features which draws certain players to GURPS.
I played a quick demo of Dungeon Fantasy combat at Gencon and now have access to the digital rules and there is one aspect involving combat that immediately strikes me as problematic (to my way of thinking). Dungeon Fantasy does not use the second-by-second countdown of full blown GURPS combat, which is fine. GURPS is a toolbox and using more or less detail is part of the individual customization the system is intended to support. Dungeon Fantasy streamlines combat to a degree and for many, running combat as written in Exploits may seem appropriate. I find myself uncomfortable with characters/monsters moving past each other with no hindrance or opportunity to attack, however.
Therefore I will be trying a houserule when running Dungeon Fantasy, (which I hope to do soon) one which introduces a zone of control mechanic. Dungeon Fantasy uses "facing" for creatures. The hexes to their front are front facing. Only movement, attacks and parries across front hexes are unpenalized. Side and rear hexes offer attacking opponents position advantage. I think the front hexes should constitute a zone of control. Creatures who enter a zone of control, or who start inside such, should be limited to a single hex of movement. This will prevent moving past or very far out of the threatened area of an active opponent. Casting while in a zone of control (ZOC) seems unreasonable as dodging and parrying would make it virtually impossible to concentrate on the spell and perform the gestures and vocalizations necessary for casting. Similarly, using a missile weapon while in a ZOC seems impractical and I will houserule that as not possible.
I frequently try various houserules (discussing them with players before the game, of course). Often I find the houserule doesn't work out the way I hoped and I abandon it for the next session. Other houserules seem to work and I have been using them for years. The only way to know for sure is to test it out during play and discuss the results with players afterwards. I may find Dungeon Fantasy works better using the rules as written, but I am bothered enough by the idea of hostile beings moving freely past one another to want to "fix" the situation. We'll see how it works out in play.