I much prefer them apart. Here is a link that might be useful:

Not all crape myrtle pruning is 'murder'. Detail pruning, the kind that directs growth, opens up the tree to good sunlight and circulations, is great! I can make a so-so crape into a piece of sculpture in 30 minutes without doing any 'topping' whatsoever. Ornamental trees and shrubs often benefit from intelligent and reasonable pruning. Walt, I find nothing objectionable about the pruning I observed on your trees. Dan, here's a story I've told here before, but before you joined us: I was called as a consultant to try to find out why nearly all of the large trees planted on a new construction site were declining rapidly after several weeks. I knew without getting out of my vehicle that they were all planted too deeply. That was the sole reason for the problems. In the SC heat, the trees died within a matter of a couple of months. At this inspection were the landscape architects, the landscape contractors, and the property owners. After I removed the mulch and dug down several inches, we came across all of the ropes AND straps AND wads of burlap still in tact. When I asked why, here's what the landscape architect said: "Oh, I asked that they leave all of that there so the trees would be easier to remove if they died." A SAD, but true story, lol!

Siren Red is nice too, but a smaller tree than Dynamite- Monrovia's site says Red Rocket only gets to 6-12 feet tall and 5 feet wide- that could be a good choice depending on the size you're looking for, but I really needed something bigger (I wanted something that would provide some nice shade and at an eventual 15-20' tall, 10-15' wide, Dynamite was a better choice for me). I considered Red Rocket too, but that variety seems even harder to find than Dynamite in my area (no one I talked to had ever seen it), and the difference between the 2 seems pretty minimal to me. Anyway, I planted my Dynamite today, so we'll see how it goes. I'm starting to think the guy at Armstrong that said all that stuff in my first post may have been confused or something.

the base problem.. is that .. as a babe.. it was planted for the size of the plant at point of sale ... with no real concept of its future potential ... once it stated growing.. 1 or 2 feet from the foundation .. there was no choice as to pruning ... but crape murder ... its simply to big a plant.. for where it is planted ... sometimes its easier to cut bait ... and start over ... and either plant it a bit further away ... OR ... buy a plant with smaller potential ... OR ... properly prune it every other year or two ... on the other hand ... [its never simple... lol] ... and do understand i have never had a CM up here in MI ... so i will defer if i am way off base ... you might try hardcore renovation ... go in there and remove the largest 1/3 of the trunks ... trying to get it to resprout way down low ... next year ... take the second third ... etc ... inside 3 years .. you will have refreshed the whole plant.. to new vital growth .. which you can train properly over the years .. [until you move and leave this nightmare for the next peep .. lol] .. upside here .. you learn a lot about pruning ... downside ... its right in front of the house .. perhaps not the best place for such an experiment ... https://duckduckgo.com/?q=renovation+pruning+of+crape+&t=ffcm&ia=web when i bought my first house.. there was a slew of 40 year plus shrubs... and i wanted to save them .. for the history of the house ... 5 years later i removed the last nightmare ... one of the happiest garden days in that garden ... pshaw on house history .... after all.. i didnt keep the paisley 3 inch shag rugs either.. lol ... https://flashbak.com/selling-harvest-gold-shag-carpet-ads-from-the-1960s-1970s-385094/ play around.. learn to prune.. but keep it in mind.. that removal might be the best answer ... of course.. if you are an instant gratification type.. just do it now ... ken